What gives you the impulse?

As I’ve started learning my camera and have taken more pictures, my mind is more in picture mode ever day. I see more things I want to take photographs of, I see more things I find interesting in different ways, but I can’t always say why. What triggers that impulse to lift the camera and take a shot? Light, situation, contrast, patterns? Looks like my hard drive will soon be filled up with mundane photos that aren’t interesting to anyone else than me. But that’s why I do it, I suppose. I take the photos because I like them and the act itself fills me with childish joy. I take them for me. It makes me happy.