During my mom's last remaining years, she developed severe short-term memory loss. The doctors said it was a form of dementia but not Alzheimer's. Anyway, she would forget where she put stuff all the time - she wasn't hiding things, she was putting them "away". Then of course she couldn't find them and accused whoever was around of taking it. Then much later, when she would find it, she wouldn't tell anyone because I guess she would be embarrassed. So then someone would see her wearing the pin that had been "stolen", but by then she had forgotton that it had been "stolen" and told us we were crazy and denied ever saying such a thing! Although it may seem funny, it really got to be a very serious thing and became very hard to live with. (She lived with me the last 4 years of her life and with my sister for 5 years before that.) The condition just got worse and worse and could have been anything from her crochet hook or a knitting pattern to her wedding ring or cash or a check. It also involved depression and anger. You had to constantly remind yourself that this wasn't her, it was the disease, but it was still hard.
She is resting in peace now, and even though it was difficult sometimes, I miss her so much.
I don't think I'm developing dementia, but I sure do "misplace" things - I just say a prayer, even out loud, to St. Anthony, and whatever I couldn't find always miraculouly turns up!