I've been a night owl all my life. I'm always up late at night.
Same here!  I usually stay up until 2 AM!
Night owl (person)
A night owl, evening person or simply owl, is a person who tends to stay up until late at night, or the early hours of the morning. Night owls who are involuntarily unable to fall asleep for several hours after a normal time may have delayed sleep phase syndrome. 
The opposite of a night owl is an early bird – a lark as opposed to an owl – which is someone who tends to begin sleeping at a time that is considered early and also wakes early.
long-term commitment to the music industry in an interview:
When I play, I am very much in the space where I was when I wrote the music. You could slay me quite easily, I'm at my most vulnerable. I am very private, in all aspects of my life, to everybody, so why is it that I get up on stage every night and open myself in front of strangers? I'm not sure if I've got the bottle for it, any more.
Marling