I'm surprised that some of you have trouble understanding some of the lyrics to "Sex, Drugs & Violence". I don't know, I might be wrong, but here's my interpretation:
For me, the song is about a troublemaker (all my life trouble follows me like a mystery girl) who has now grown up and is feeling a bit bad about how he never made an effort in school and has missed out on learning many things useful to an adult (back in school it never made much sense, now I pay but I can pay attention, teaching me the hardest lessons of my life). He is trying to catch up on everything, but falls back to his old habits sometimes. So the "Sex, drugs and violence, English, maths and science" part is a comparison between the two very different ways of coping with life, and the "safety in numbers" line is pointing towards the fact that math formulas are always the same and thereby bores him and makes him look for danger (gimme gimme danger) instead.