I was chatting to a graffiti artist. He'd been participating in the 'Battle of Waterloo 2011', a graffiti event in London. Graffiti is his life. In his spare time he made graffiti art in his home. To celebrate his birthday, he had a wonderful 3-D-effect graffiti-style tattoo done, his own design, on his arm.
It's a whole world in itself. A 'battle' is a contest of skills. 'Tagging up' is signing your work. To go out 'bombing' is to go and write, to cover a place with your work. Sometimes the artists get into trouble, go one step too far.
To get so involved in an activity is to take part in a whole subculture, with its own heroes, language and style. It doesn't matter what it is, as long as you're not hurting anyone. Go and do something that fulfils you.