Should i join the navy?

Heres my situation: currently enrolled in a University. So far its going ok but I don't feel like its where I need to be. I cant really focus on my work because honestly this isn't what I wanted to do. I was pressured into it by my brother who cant fathom the idea of me being in military service. Since I was a child its always been my dream to enlist. My father did it, his father did it, etc. Its almost like a right of page on his side of the family. Also i made a vow to myself I'd never take anything without giving something in return. Having been on welfare and food stamps most of my life, I feel I need to give back to the government which took care of me for so long. I'd like to know if my motivations are just. Also I'd like to hear expierences from some people who have served in the navy so i have an idea of what i can expect. Thank you !