I'm very, very new to reading comics. Decided to start reading "The Flash" (New 52, 2011), read through issue zero. They show Flash's orgins, but it's kind of like "OO, I got superpowers! Gonna make mah custume and gonna go stop crime!"

From the older series, I can see that Barry Allen, was a big fan of Jay Garrick as the Flash in the old comic books, having the similar powers, he took up his own mantle of that hero. But the purpose?

Purpose, as in: Batman became a superhero because of his parent's death, he wanted avengence, and wanted to make sure this would never happen again. The Flash, I can't find a reason why he decided to put on the costume. Help?