When my Betta Malcolm was young he'd glass surf dusk till dawn, absolutely nothing else, he'd also bite his tail and tear chunks from it. I was very disappointed, it wasn't the experience I asked for. I considered giving him away because I couldn't deal with it anymore.
After 3-months surfing he saw his reflection in the rear glass and gradually stopped, also stopped biting his tail as he matured. Now he's full grown and 'really chill', he spends hours meditating on his mountain and has a beautiful long tail. Although it originally wasn't what I asked for I wouldn't have it any other way now, he turned into the best Betta you could ask for.
Here's a picture off him when he was around 1-year old.
(He's over 1.5 years old now)