My problem is that I get too much sleep and it's very difficult for me to wake up if there's no meeting scheduled that morning for my flexible remote job or if there's no social pressure to get up. I'll happily sleep 12-14 hours if you let me. I've been this way since I was a teenager, and I'm 25 now.
I know this sounds like I'm complaining about a luxury, and lack of sleep is definitely worse, but it's always made me feel like I'm wasting my days sleeping and missing out on life to a degree.