When you have reading glasses all around your apartment, one at the computer, one on the coffee table, one in the kitchen, one in the library and one in the bathroom, just so you never have to say, “Where the hell are my reading glasses?”, and you make the joke that that the only time you forget where they are is when they are on your head, and you get up to go to the bathroom and you come back to the computer and your reading glasses are not there on the table, and you finally realize they are on your head and that the joke has become reality.
I don’t do that with glasses (although I do have a couple of pairs of cheaters stashed around) but I do it with scissors, rolls of scotch tape, metal nail files, chapsticks (or the like), and packages of dental floss (is that last one TMI?). I can never find these things, so I just buy lots of them and strew them everywhere. Even so, I can hardly ever find a roll of tape when I want it. And I live alone, so hard to find anyone to blame.
Well , I can never find the fucking scotch tape or nail files but I don’t use them that much, don’t need multiple copies around the apartment. But how can you not find dental floss, it sits right by the toothbrush, right? I don’t use it anymore, I have dentures, but even I would find a way to misplace it.
Ah, grasshopper, you have much to learn. And forget.
I have a neoprene knee wrap because I strained my MCL yet again, and I misplaced it about an hour ago. I spent some time carefully limping and checking around the room, and finally my 21yo son looked up and said, “um, didn’t you slide it down your leg a while ago and now it’s on top of your sock?”
I’ve had to develop the habit of “putting things away” because of unauthorized migration. Like taking the 2 extra steps from the counter to the hook where my keys hang. Or putting the scissors back where they belong right after using them (most of the time.) Or keeping track of my phone (it was so much easier when I had that cheapie flip phone that tucked easily in my pocket!)
Of course, the problem is exacerbated by the other three adults living here - if my scissors are missing, I have to do multiple interrogations to track them down! And we won’t get into the adventure last week when the toddler put the TV remote into a box that then went out to the recycle pile - it was sheer luck that I found it!
So in my case, it’s not senility so much as these people who live with me! 
Seriously, go to amazon and order 10 pairs of moderately-priced scissors and put them everywhere. Kitchen, desk, coffee table, bathroom, next to every (adult) bed in the house, garage, and stick a couple in the car, for good measure. That way you never have to walk across the room or across the house to “put them back where they go.” This will improve the quality of your life immensely! 
I do have multiple pairs, and at least 2 are in places that no one would think to look so they’re always available. But I want the red-handled scissors to stay in the kitchen. For some reason, that’s the pair that grows legs. I suspect even if I had half a dozen pairs in an attractive vase, they’d still disappear. These are the same people who ask me multiple times where the Pyrex baking dishes go every time they unload the dishwasher!!! I fear they’re untrainable.
Funny thing is, scissors are the one think I never lose. They are in the kitched drawer, mostly to open food packages. And since I have a studio apt, if I have a package that needs to be opened, I take it right into the kitchen. But I’m sure I will mangage to lose them someday
I’m fond of saying: “I forgot more than you’ll ever know.”
It keeps those uppity youngsters in their place. 
I lost a bag of garbage Sunday. We had an outdoor dinner party with social distancing for my gf’s family. I take our garbage to work with me and dispose of it in my work dumpster. My gf’s nephew offered to take a full bag down to the garage.
After everyone was gone, I looked for the bag of garbage in the garage but couldn’t find it. Looked in my vehicle, in my gf’s car, in her truck, in the basement, in the garage, etc. The next morning she looked everywhere and couldn’t find it.
She eventually texted her nephew. It was the one place neither of us looked and wouldn’t have looked had we continued our search. It was in the big trash can in our garage. We never use it and never thought to remove the lid for a peek,
I’m nearing 70. Today I was talking to myself (as usual), but for the first time ever I stopped, hesitated, then asked: “What did you just say?”
- That was funny.
- It can happen to anyone, really.
Made me laugh out loud.
Meh, senility should just be laughed away. If you find yourself rushing downstairs or upstairs to get something you need, and when you get there you’ve forgotten what it is you came for, then you’ve reached my level of senility.
Among my favorite things to lose is one of my drink or wine glasses, because I tend to carry it around with me as I bustle about and sometimes put it down in odd places. Being somewhat obsessive, it really bugs me when I lose one, and I tend to go on extensive searches for it. It’s really grim if I happened to be down in the basement and set a drink glass down there, because that tends to be one of the last places I look. My favorite rum glass once languished down there for many days, sitting on top of a box, with rum still in it. 
I’m sorry about your sore knee, but this did make me chuckle.
I do the scatter technique with scissors, letter openers, hair brushes, glasses and prandin (meds). I finally put all my tape products (Scotch, duck, time, packing) into a big basket - that has actually reduced aimless wandering around looking for something sticky. I’m kind of surprised at how many partially used rolls of tape I have.
This morning my wife brought me coffee. Thank you darling. Ten minutes later she asked if I could make her an eggs with bacon bits wrap while she took her shower. Well, of course.
I turned on the burner, and started heating a tortilla. I grabbed a cup to stir the eggs in, took off the tortilla, cracked the eggs, got the bacon bits, and got a fork to twirl the eggs in the cup.
The cup, however, was empty. And my coffee cup was full. Yeah, the light was dim and the cups were identical dark gray mugs, but even so — disconcerting.
(After cooking new eggs for wife breakfast, I emptied most of the coffee from my mug — leaving enough to cover the eggs. They got zapped at full power for 30 secs., and then zapped at 20% power for three minutes. The last of the coffee was poured out, and the eggs topped with bacon bits and hot sauce. They were fine, kinda like poached, but not as moist as most poached eggs.)
one for me is I ask the husband a question and less than a minute later wonder WTH he said.
the other is the black holes in my house, look for anything, on my desk for example, looking for my phone, for example, it isnt there when I look for it on the desk, hell it could be the TV remote for that matter. I start looking, give up and come back to the desk, there it is, right where I left it.
Turkey black holes!!
How about when you go to the refrigerator and you suddenly have to stop and think, “was I going to get something out or put something in?”