That is the best solution.
I ran into this one as a rightie in a British former colony. My rental car had left hand shifting and right hand wipers, so I would instinctively shift with the wiper and stall at every stop light.
Virtually everything that is not symmetrical in form and function. Since most things are designed by righties for righties, righties generally never have cause to experience this, much less think about it. The things listed so far in this thread barely scratch the surface. It’s a long list.
for the longest time I thought I was just too dorky to throw one, when I finally found a lefty Boomer (some 15 years later) I was like :smack: Now I have a couple dozen and make my own practice rangs.
Coffee mugs, some have the handle is slightly off vertical favoring righties.
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Along the same thought, I’m a lefty, and I’ve played both french horn and trumpet. I found the fingering on the french horn so much easier than the trumpet because you use your left hand for fingering.
As for the original question, I’d say twist-off bottle tops. If you’re a lefty, it’s hard to grasp and twist the top with your left hand. Try it sometime. The only way I can consistently open bottles easily is to turn the top with my right hand, or hold the top with my left hand, and turn the bottle with my right hand. Also, any spatulas or spreaders that have a serrated edge on them mock me!
One that annoys me is glass measuring cups that only have the markings on one side.
Rulers can also be awkward to use when you’re lefthanded.
And I don’t think anyone has mentioned wrist watches. When you wear one on your right wrist, you have to really twist your left hand around to get to the stem if you want to fiddle with your watch without taking it off.
I thought it was worth repeating these quotes…this one is only about habit. If you’re familiar with using one hand, then using the other is awkward. If cards were ‘handed’, the pedals would be switched as well.
Some cake decorating tips are used by only right- or only left-handers.
Hockey sticks, although it’s my understanding that most right-handed people shoot left and so there are more left-handed sticks. I am right-handed but also shoot right.
Bugger, I quoted wrongly earlier. The quote about wipers is irrelevant - the car industry has gradually settled on left-right standards. The point about having a gearstick on the left remains.
What you’re missing is the anal teachers that through a fit if you do it. Makes it harder to stack the papers or some BS like that. Loose Leaf is the best happy medium for me.
A lot of things you wouldn’t expect to have biases in their handles. Power tools like hand held drills and jigsaws, those staplers for wood, pruning shears etc. Anything that can have a handle that’s made more “comfortable” by its shape is pretty much going to be uncomfortable in a leftie’s hand.
Anything with numbers printed on it for measurement is on the wrong side for lefties. Though in a measuring cup’s case you could argue that it’s the spout the wrong way round, not the numbers.
Anything that has an edge on one side is wrong too. Things like a sickle or those tools to make lines in plaster and other objects with blades (excluding those with a horizontal blade).
Even things like lightbulbs are meant to be most easily screwed in using the right hand.
On the plus side, though, there is evidence that shows that after a stroke on one’s domenent side, Lefties often fare a lot better when it comes to learning how to use the other hand for tasks than righties do. And we think quicker 
Playing cards - can only be fanned and read comfortably being held in the right hand.
Men’s clothes - many shirts have one breast pocket, on the left, easy to access with the right hand. And when pants have one rear pocket, it’s on the left, for a wallet that is pulled out with the left hand and then reached into with the right. Buttons and zippers are oriented for right-hand use.
Screw threads - twisting a screwdriver to the right (clockwise) can be done more comfortably and with more torque with the right hand.
Pencil sharpeners, coffee grinders, meat grinders, egg beaters, etc. - made to be cranked with the right hand.
Cooking spatulas bent where the handle meets the blade and with angled leading edges - easy to use with the right hand, near impossible with the left.
There are hundreds, if not thousands, more that will come to mind eventually.
You could use fixtures and bulbs from various public places. The bulbs thread in counter clockwise to discourage theft.
Hmmm! Maybe that explains why I’ve never figured out how to use a lot of the tips my right-handed mom had – the kind for making roses and such.
And in the same vein, my sister and I have given up on learning calligraphy. The nibs are designed for right-handers. There are left-handed nibs, but I’ve never been able to figure out if you use them with right-handed strokes or reverse the strokes. 
Imagine my surprise when I bought a carrot peeler and found that only the right-handed blade was sharp.
I eat, write, and throw left handed, but I shoot pistol right handed just for that reason – not down the collar so much but I did quickly get tired of getting smacked in the temple.
When I was watching Saving Private Ryan the first time I kept thinking there was something odd about Jackson’s (the sniper played by Barry Pepper) shooting. It suddenly struck me during the grand finale: He was shooting left handed and reaching up and over the top to work the bolt on the right side.
IANALeftie, and this will apply to approximately Zero of you here, but knitting instructions always come right handed.
I’ve taught a leftie friend to knit.
I’ve also tried to retrain my brain to use the mouse left handed. The mouse was all over the place like a couple of drunks in the Dodge Em cars. I’m pretty sure my left hand is retarded, or something.
Because of hearing loss in my right ear, I use my left ear, and have discovered to my dismay, that cell phones have buttons on them that normally wouldn’t be touched and I am constantly de-activating the cell phones ringer to silent mode and it takes me weeks to figure out how to put the ringer back on. ( I just give it to my husband and say, " Here. Make it better.")
Eh? Most doors (internal ones especially) are one way around on one side and the mirror way on the other side. A right handed door on the outside is a left-handed door on the inside, in the majority of cases. What kind of doors had you in mind?
Obviously scissor have been mentioned but the molded plastic ones that are made for the hand…just not mine, piss me off. They don’t have to make things lefties acuallly find it uncomfortable to use.
And as a photographer I’ve always been put off by having the shutter on the wrong side. My new digital camera is obviously built for the right hand. I’m being oppressed!!!
It’s just as well that you don’t try to learn calligraphy as a lefty. Unless you write upside down (I’ve seen some lefties do it), you’ll drag your left wrist and arm across your just-inked writing, which makes a big mess.
I’m the only righty in our three person household. I’ve tried to teach my daughter how to knit, crochet, and other handicrafts. It’s frustrating for both of us.