all about the chase?

so i was talking to my friend about this guy i’ve been talking to. in the beginning he was all about me and tried so hard to get me. but now that he has me he’s changed so much. like he doesn’t text me at all and only snaps me every few hours without saying anything. my friend said that the one thing about guys is that it’s all about the chase. i’m kinda confused what that means can someone help me out