Have you ever wondered if you closed the garage door, or turned off the stove. How about putting out food for your pet, or watering the plants. Aging reduces these mundane acts far to the back of our consciousnesses. If these niggling things bother you from time to time, try clapping. When you close the door or other mundane activity, clap your hands. Alternatively, you can say it out loud, "I closed the garage door."
Sounds silly, but your mind will file those actions away much more
prominently than the act itself. When you doubt whether you turned
off the stove, your mind will rapidly remember you said it out loud
Here is another mind trick for those times you go into another room
to find or do something, only to discover you forgot why you are
there. Going through the doorway is like passing through a barrier
and it changes your thought process. When you decide to go to
another room to retrieve an item, say it out loud, "I am going to
the kitchen to get some potato chips". Of course, that is one
activity that I would never forget, but you get the idea.