I don't really have any problems sleeping, it is more about getting to sleep in time if I have to get up at a certain point that can be difficult. If there is no specific time where I have to get up, I can easily just roll over and go back to sleep if anything wakes me (unless they are loud...
I try my best to go to bed around 1-2 am, but often it will be 3 or 4 before I actually make it to the actual bed (good thing I'm starting night shifts soon, which will put me in bed sometime after 8am on the days when I work), I have to force myself to go to bed because if not I can easily sit...