One of the things I love about bettas is that they have so much personality! Especially when you give them the room they need. Not many other fish actually have personalities. They just kind of swim around. They're relaxing to watch, but they aren't very interactive. I went to a LFS a few weeks ago and I was just going through the aisles looking at all the different fish they have, and I looked up and there was a tank on the top shelf, the bottom was level with the top of my head, and it had a bunch of Koi in it and they were all swimming in the bottom corner of the tank, bumping their noses into the glass, and I was like WTH is wrong with them?? So I walked past, and THEY FOLLOWED ME! Lol. So I played with them and kept walking back and forth and they kept following me. So they were interactive, but I think it was just because they wanted to be fed. lol.
Anyway, betta fish interact with you just because they feel like it. It's really interesting how they can actually recognize you. My parents came over the other night and were sitting on the couch next to Fishie's tank, and I was telling them how epic he looks when he flares, but he wasn't flaring, which was weird because whenever I turn on the light in the tank, I think he sees his reflection, and he swims around flaring for a really long time. So anyway, I tried to get him to flare by putting a mirror up to the tank right in his face, and he wouldn't flare. Then I put it in the water and he still wouldn't flare! That's not like him at all because he flares at everything. Sometimes he flares at me when I get close to the tank, and he just flared at a Pepsi can next to his tank... So anyway, when they were leaving I walked them out and when I came back upstairs and he was flaring! haha! I think it was because he didn't know my parents, and he was nervous around them, so he wasn't flaring! So interesting!
Sometimes he'll come up to the glass and watch me. If I put my finger on the glass he either backs up really quickly or he stays there and wiggles his butt.

He's very inquisitive and curious and whenever there's something new or something he notices for the first time, he'll go up to it really close and stare at it for a while.
When he gets really excited, he poops. haha. I'l turn on the tank light, and he'll swim around flaring and pooping. it's so funny.
Anyway. this is just a post appreciating the personalities of betta fish.