I go to bed pretty late
Same here.  I'm a bit of a night owl.
What do you think causes someone to be like this
Some people like to create habits like an owl!  That's where the term comes from, people up when owls are up lol.
I see. Is there any medical factor against it?
Some night owls may have a disorder involving there sleep phases.
i see. But i like what i am. Is there any therapy if you want to stop being a night owl
Excuse me, their* sleep phases.  Had to correct my grammar.  I think some people are just "A People" and some people are "B people" when it comes to sleep.
It is ok. Have you ever been a night owl ever since you were a child. I started this as a teen
night owls may stay awake until just before or even after dawn. Night owls tend to feel most energetic just before they go to sleep at night. 
Some night owls have a preference or habit for staying up late, or stay up to work the night shift. Night owls who work the day shift often have difficulties adapting to standard daytime working hours.
Night owls have often been blamed for unpunctuality or attitude problems. Employers, however, have begun to learn to increase productivity by respecting body clocks through flexible working
that's what I want to be, a legend in Irish sport. I think it's coming up to 30 years since Barry won his world title in Loftus Road against Pedroza and people are still talking about it. I want to be like that 30 years from now – people are talking about my fights with guys like Chris Avalos and Kiko Martinez in the pubs all over Ireland. That's what I intend to do. I want to create a legacy. I want to keep beating big names. I want to