I do that, but not because of senility. There it is, a great CD at Half Price Books for $4.99. It will not be there the next time. Do I own it? I have too much to be able to remember. Best to buy it and check later.
This is a symptom of some problem, just not senility.
They allow you to hold it for up to seven days...so you can go home and check. -_-