Why not get close to a stranger?

One day I was entering the gym and I saw this boy that I have never seen before. I was just there to play some basketball and I as I was putting on my shoes he comes over and says “Hey, I don’t know you but do you think I could join your basketball team?”. I was kind of shocked because I have never had anyone ask me before but I said “Yes, that is totally fine, I need more people”. He got the biggest smile on his face and said “Thank you so much”. I was so happy that he was so happy, I hope I see him at the gym more and we can become friends.