We probably all have been doing that.
It's starting to be late,
you are beginning to get tired, but you continue surfing the web.
You just continue,
not because it's very fun, only because you don't ask yourself the question.
You see the time:
11PM...
00AM...
1AM...
2AM...
At some point you think "I should go to bed", but you don't answer yourself, and continue.
If it is currently the case, or you already have experienced this, comment here. Say how you feel, what you think, etc.