Today I found out that my 23 year old daughter thought that when the oil light comes on in your car it is like the low fuel light, meaning you can ignore it for a while! I quickly disabused her of that notion.
What things have you been surprised to find your kids didn’t know?
Not my KID, but I was surprised when my baby sister called me needing instruction on changing a flat tire. She is so generally uber-competent that I found the gap in her knowledge difficult to credit.
How to use a payphone. It just never registered to me as something that someone once taught me how to use, but my son did nearly get stranded one day when faced with a dead cell phone and one of the last payphones in existence.
I guess it’s really not a vital skill these days. These days you can probably find a cell phone to borrow should you really need to. But it’s something I assumed he knew.
There was a recent episode of The Middle where the older son is trapped in the library after it is closed and locked up. For whatever reason, the only phone is the rotary phone on the desk and he has no idea how to use it. Makes sense!
This wasn’t a kid, but a FOAF, who thought you could only pay as much as the minimum payment on your credit card bill. :eek:
In the car, picking up a friend’s 12 year old boy:
he asked me to lower the window on his side. I had to explain to him that in my car , the way to move the window is to you put your hand on the lever with the round knob, and rotate it a few times.
He said thought that was weird.
I suppose he’s right.
(one day, I’ll show him my 8-track tapes) 
Perhaps she thought if there was a real problem, the light would get brighter or there would be a buzzer.
I was stunned to learn that my 12 year old daughter cannot tell time on an analog clock. Her entire life has been digital.
I’ve seen this with increasing frequency.
My younger son decided he wants to collect vinyl records (totally out of the blue, I have no idea why) so we got him a turntable for Christmas. I doubt he has any idea how to put a needle down on the record. And even though he has a culinary degree I doubt he knows how to make popcorn in a pot on the stove.
Tie their shoes. Still a lot of shoelaces in the world but their skills range from rudimentary to none.
When my nephew J was a much smaller lad (he’s 12 now), whenever Mammahomie would take a picture of him, he’d grab at the camera and say “Me see! Me see!”
Mom still uses cameras with film.
How old are your kids?
This is something my parents thought I knew. When I was around 10 or 11, I was playing with some young relatives. I’d designed this game where I hid an object then drew a map with cryptic hints leading to the hiding place. For one round, I sealed the object in a plastic ziploc bag and dropped it . . . in the toilet bowl. When the little girl, who was around 4, found it, she was ecstatic and ran to her mother and my parents, arms soaking, yelling about how they’d all rooted around in the toilet bowl.
When my Dad gave me the “You didn’t actually do that, right?” look, I made the argument that the toilet bowl was actually he cleanest place in the house because it was washed every time someone flushed. I didn’t get the concept that not seeing any grime didn’t mean it was sparkling clean.
How to fax something.
My son’s in college and got a jury duty notice. I called for him and found out he needed to fax his student ID and class schedule to be excused from jury duty for a year.
He had no idea how to do it, or where to find a fax machine. He emailed me stuff and I faxed it.
Although in her defense most newer cars also have an oil level light which, unlike the oil pressure light, you are safe to ignore for a while. Of course they only had to start putting those in because damnkidsthesedays don’t know they need to check the oil regularly.
Fax machines aren’t something everyone has ever known, though. They were much more common for businesses than they ever were for homes. My family certainly never had one, nor did most people I knew.
My then 17 year-old son had no idea where to put his return address on a letter. He never sent letters - he emailed everything. I guess he’d never noticed where it was on any mail he received. Startling! What do they teach in schools these days.
Same child at age 5 was so excited when we rented a cottage with an old TV. He couldn’t believe a television channel could be changed simply by turning the knob on the front (removing the need to hunt for the remote).
A friend once told me the story of her son and his friends hanging out at her house, going to the refrigerator for a drink and and the friends being unable to figure out how to get the ice out of the blue plastic trays.
Don’t most new TVs still have small buttons somewhere to change the channel (under a flip panel or on top of the TV behind the screen if not in plain sight) or have those been completely removed?
My 13-year-old daughter broke the tray trying to figure that out. She also had no idea how to operate the (cordless, digital) landline phone when we installed one here last winter. She’d never used anything except a cell phone.
None of my kids get my pop culture references, but I guess that’s to be expected. Still, I was perplexed when they had no clue what I was talking about when I made a Gilligan’s Island joke.
Mostly, though, my kids are pretty good with the practical stuff - if they don’t know something, they know how to find out, which is good enough for me. My 20-year-old houseguest, though? Oy vey! The list of what he does know is so much shorter than what he doesn’t. A couple of weeks ago, he was complaining that the light in the trunk of his car wasn’t working. I told him to make sure the light bulb hadn’t loosened due to vibration, and that, if tightening didn’t work, he could get a new bulb at the auto parts store. He informed me that the light didn’t use a bulb, nor did the dome light in the interior. (Mind you, this is a '97 Mercury Marquis - the equivalent of a Crown Victoria. If my husband the cop knows anything about vehicles, it’s Crown Vics!) I just kind of sat there staring at Vinnie, waiting for the punch line, but my husband finally asked him what species of idiot he really is… 
Same kid, same car: The rear seat has become loose somehow - not attached to the frame of the car. I was trying to tell him that’s very unsafe, for everyone in the car, and that he needs to re-fasten it. (Which led to a discussion about impetus and physics, and the poor guy was very, very confused by the notion that the seat would fly forward in relation to the vehicle if he came to a sudden stop.) Vinnie informed me that the seat was never attached to the floorboard. :dubious:
He also doesn’t know how to check fluids other than gasoline and oil, how to check tire pressure, how to change a tire, how to change a wiper blade, how to change an air filter, and so forth. He’s bumfuzzled at the notion of anything to do with home repairs or maintenance - from changing air filters on the HVAC system to twisting a threaded pipe when a faucet works loose to programming the remote if the batteries died. The very notion of looking something up is beyond him. I really don’t know whether to pity him or to ridicule him. If he showed the first ounce of gumption, I’d go with pity, but he’s perfectly content to be a complete idiot, so…
Most cars nowadays only need an oil change every 5,000 miles. Checking the oil regularly is a waste of time unless you’re driving a vintage automobile.
And not oil lights and gas lights are created equal. The gas light on my old Pontiac only turned on when the tank was literally empty. If you saw that light, you had about five minutes before the car completely shut off.