Breaking up when there was no commitment?

Last night I did my duty and broke the casual thing with Julie off clean. It was a little sad, she's a sweet girl and didn't deserve meeting a dude like me. I'm pretty incapable of forming any serious attachment but come off like I can (that's fucked up). Being a man that only knows serious relationships I don't do the best job of keeping it loose and casual, I've never learned that lesson. I guess I'm learning it now.

I went home feeling like a severely unwashed ass. I text a newer friend whom I have a growing respect for and seems to always be awake at 4 am. I've gotten the impression that she treats dating as more of a sociological experiment, with tactical precision, more from the viewpoint of an observer than a participant. I might be wrong, but she has good insight. I said something to the effect of my second sentence to her, she replied " ... and that's a crying shame."

Initially I thought that was a shitty way to be, but quickly realized she nailed it. 

I'm not saying I will embrace an utterly uncaring attitude, I prefer a degree of sensitivity. However I need to toughen up a little. If I can, I will probably do a more responsible job of dating where I'm not sucker punching anyone then hating myself for it after. Its a game, I'm beginning to understand the rules and devise my strategy.