I snore, though it depends on what position I sleep in and my weight. (My weight fluctuates depending on where I'm based and I certainly snore more if I'm above the norm.)

I think most people that snore know they do. Although you usually don't notice it, sometimes as you drift to sleep it can wake you up. Also others - family members - will tell you. A girlfriend once told me she liked it because it meant I was still alive. It didn't seem to disturb her.

When flying, if I think I'm going to fall asleep I usually warn adjacent pax of the horror that they might be faced with and tell them to wake me up if I disturb them. It would be difficult for me to sleep if I thought I might disturb someone.

So far I've never noticed being woken up by anyone... but perhaps they woke me without my realising it was them.