I couldn't find the small Swiss army knives, one for me and one for my husband, which we normally carry when we go trekking.
When we go hiking in winter we carry backpacks that convert into chairs so that we don't need to sit on the snowy ground when we have lunch.
At the end of the season, I was sure that I took these Swiss army knives out of those packs and put them inside our standard trekking backpacks.
I spent a lot time looking for them and finally gave up and went to bed, thinking I might remember the following day. I didn't. We went trekking without them.
During lunch, my husband found his knife in his backpack. It was inside the bottle holder on the side of the backpack. I vaguely remembered that we used it during the last trip and put it there temporarily and forgot about it.
Where was mine? That was my next question. If I put my husband's in his backpack, I must have done the same thing with mine. I emptied my backpack but still I couldn't find it. Then I put things back and .... found it! It was tied to the side strap inside. That was the first time to put it there, but I thought it was a good idea at the time, so I wouldn't lose it.
Things like this happen often now. The only things I seem to remember well are the IDs and passwords for my PC, smartphone and tablet.