What da reason for this?

[Albert]

Repeating ticks, like what David said, is most likely due to him either lacking material to perform or lacking the confidence to perform other tricks.

I don't remember what I was like when I started out magic, but when you first learn it, you want to perform it for someone so badly because you are excited about learning something cool you can showoff. That is also probably why he isn't patient enough to refine his moves before showing off.

A good alternative may be for you to show something so good to the usual crowd your friend attracts. Something so good that without practice, your friend can never ever surpass you. This builds up reputation of who you are and what you are like. You are also in a good situation to do so since people can compare you to him.

I had a good friend named Shane once, and he was a hardcore Criss Angel fan: dressed like him and did black magic stuff (with fake blood, etc.). Although he took more initiative to perform to people, one of the big reasons why he wasn't as well known in school as a magician compared to me was that he lacked the presentation and the practice to really pull off his tricks. To the spectators, it was cool, but that's all that was. It wasn't magical enough to make people ask him for more and more and more.

I hope that sort of answers your question.