Mystery Customer Tips Generously Every Time

So I work at a busy coffee shop and there's this guy who comes in about once a week. He always orders the same drink, but here’s the weird part: he tips like 50% of his order every single time! It’s not a huge amount, like $2 or something, but it feels excessive compared to most customers. I’ve never seen him do anything else special at any other shop and this is only one coffee. So why does he keep doing this? Is there some kind of hidden meaning or should I just assume he has too much money and wants to spread the wealth around?