A joke I just made up

Four college students are sitting down to lunch.
The first college student says that she is a psychology major and hopes to one day council couples with troubled marriages.
The second student says that he is majoring in economics and hopes to one day become a financial advisor and help young people manage their finances sensibly.
The third student says she is majoring in diplomacy and hopes to one day help small nations mend their differences.
The forth student says he is majoring all those same things too.
The first student says, "Wait. I thought you were a theatre major."
"I Am." he replies. "If I make it big in the biz and become a huge celebrity, I'll suddenly be considered an expert in everything else."