Using a CPAP is a night and day difference--whereas I used to require 10-12 hours to function without randomly falling asleep if I sat still for too long, and now I can get 6-8 without any issues and I'm more alert, have a better mood, etc.
I wouldn't have known except that my ex-girlfriend noticed that I wasn't breathing when I was asleep and got me to see a doctor about it. Apparently it had been going on for years and years--I asked other people who had seen/heard me sleep from 15 onwards and a lot of them also had noticed it but hadn't said anything.
If you think you have apnea, sleep studies suck to go through ("here, lets stick a bunch of monitors on you and then let you try to sleep"), but it was entirely worth it. If it's at all economical to do one, I'd suggest looking into it: even if they don't find apnea they might find something else.
The thing is, now I can easily get by on 4 to 6 hours of sleep, and unless I'm truly physically and mentally exhausted I'm not even able to sleep for 8 hours because I'll be wide awake after 6 hours, tops.
I have no idea whether that is my natural sleep pattern, or just because I've spent decades "training" myself to get by on less sleep because of the apnea.
I recorded myself using snorecycle. Yeah, so, my snoring gets progressively louder, until I stop breathing and wake myself up. :( It's only taken my wife three years to convince me.
Then my weekend sleep-in day rolls along and I can stay under for 12 hours, falling right back into a deep sleep even if I've had to briefly get out of bed (bathroom), because I know I don't have to get up. Unfortunately, I have to have a day like this because my sleep is so bad during the week.
I think it's related to anxiety about not getting enough sleep, which of course turns into an awful feedback loop. I've tried repeatedly to find info about this, as I am certain I'm not the only one by a long shot, but my Google-fu has failed me. Low levels of melatonin supplementation helps a bit, and at one point I was on Lunesta which got me through the night, but left me feeling only about as rested on ~8 hours as I did on ~6 hours of normal sleep, so I stopped. I can't even imagine how good my life would be without this problem, let alone if I had the kind of low sleep requirements that some do.
For me, the more I sleep and the more coffee I drink the more tired I feel.
As soon as I throw in a bunch of exercise, I find I'm asleep within 30 seconds of hitting the pillow, and I'm awake ~5 minutes before my alarm after 8 hours, and I feel good. The more exercise I get, the less coffee I drink too, until I drink none, which is when I feel the best and least tired.
Edit: 12+ hours not all the week. Most certainly a crash 1 time/w. The sleep/insommia vary each day. I have used sleep pills (make me sleep, but get grovvy all the day) and melatonin (sometimes work, but sometimes get me grovvy).
The biggest change is that I used to get migraines from lack of sleep (even while sleeping 8-10 hours plus occasional naps). Now I can get 6 a night continuously and be more alert. But most importantly my quality of life improved drammatically on account of having probably 30 hours a week of migraine-hours removed.
I still occasionally get lack-of-sleep-migraines, but they are rare, and are usually well deserved (I have three children, a puppy, and an unwillingness to give up 'alone time' in order to sleep enough. It's a bad combination).
Don't wait until you are told you snore or that you wake up a bunch. I don't stop breathing, but my breathing slows down to a point that my oxygenation levels get crazy low.
I'm still in the first month with a CPAP, but the nights that I can tolerate it, I'm waking up in a much better mood, and feel far more refreshed.
Your results may vary, but don't hesitate to get checked out!
Anyway, signs you might have apnea: Never feel fully rested, wake up to your own snoring, your sheets seem like someone pushed them all off.
If you have a partner that sleeps with you, ask them if it seems like you're choking in the middle of the night and/or your legs twitch at night. Mine is mostly the leg one, so my sheets never stay on the bed and when I was a kid I would wake myself kicking the rail off my bed.