[hiAndrewQuinn]

Well, you need to get more sleep, then. You've answered your own question.

The good news is there is probably a lot of low hanging fruit that can help with this. Quit alcohol, for one. Quit caffeine, too, for at least a couple of weeks. Screen your window, and leave it at least a crack open, if you live in a place with clean enough air to allow that - if not, air purifier it up. Try to get used to sleep masks, they're phenomenal for blocking out light, and they're really not so bad if you take your time to test and get used to them.

Past that, physical exercise is also widely known to keep cognition healthy as one ages.