Why do I love to suck my penis?

I'm 29 years old and have sucked my penis since I was about 12 years old. I don't know why but it feels good. I don't like to suck anyone else's penis, but I have sucked my own since I was a kid. I even sucked my own penis in my late teens when I was high. It feels good. It doesn't even make me horny, it's just an activity that feels good. I guess I'm just weird.