I was at PetSmart on a whim when I picked up a gorgeous blue and white betta and decided to take him home. I bought him and a little 1-gallon tank to keep him in. At the time, I didn't really think he would make any special impression on me, I just wanted him because he was pretty.
The morning after I got him, I went to feed him and he was waiting for me at the top of the tank and — for lack of better word — “wagging” his tail at me. That's when I realized hey, this guy is actually kind of cool. I observed how he carefully marked where the pellets were that I dropped and aimed for them, a big difference from the goldfish I used to have that would gulp mindlessly at the surface of the water.
I began to actually do research on betta fish and I realized I was doing everything wrong (protip: do your research before you buy a pet). There's a long list of things you need to do before you even get the fish, so I won't get into all of it here, but the subreddit /r/bettafish helped me a lot to get started.
One of the biggest misconceptions that I fell victim to was that betta fish don't need a lot of space since they live in puddles in their natural habitat. Actually, they may not need a lot of space compared to other fish, but though their natural habitats are shallow rice paddies, these rice paddies actually stretch hundreds of miles. Yes, they can and do sometimes live in puddles when the water dries up, but they have the ability to jump from puddle to puddle when the water quality deterioriates. They are not meant to live in these puddles for the long term.