I got a much better memory after I had a sleep study and found out that I have severe sleep apnea, and I wear a c-pap every night when I sleep. Sleep apnea means that I stop breathing when I exhale during sleep, and the brain does not get enough oxygen. If you do that hundreds of times or thousands of times each night, you will do crazy things like drive right by your own house, forget where your glasses are when they are on your face, try to pay your grocery bill with your driver's license, brush your teeth with hand lotion, etc.
(not that I have done any of these examples myself...)

c-papa stands for constant positive air pressure. It looks like a mask they put on you for surgery, although they come in several styles. Mine only covers my nose and is quite comfortable. I could not use the style that covers mouth and nose because I chew all night and that unseals the vacuum seal. So, It has a band that goes around your head and the air pressure comes on automatically by a sensor when you breathe into the mask when you first put it on. The pressure is not like a fire hose strong, it starts out smooth, of course, because you are awake. After you fall asleep, the air pressure ramps up slowly until it is strong enough to keep your passageway open when you inhale. It is not like breathing against a firehose; the air pressure goes down when you exhale and increases when you inhale. I promise it's comfortable, or people could not be using it already. My brain and my body feel so much better with oxygen. I don't have to take naps now, I am alert, happier, it helped my PTSD and depression, and my memory.