Need to emphasize the reasons for doing those things

 

"You are not doing those things for me; you are doing them for yourself.

"Mom and Dad are not going to be here taking care of you forever.  You'll be on your own.  Get yourself ready.

"We're paying for your schooling (by taxes or tuition, mention the numbers, how many $20 bills.)  Everyone is nice to you.  Do you know what it takes to have a dollar go the other direction?  You think people will still be so nice to you?  What are you capable of doing in order for someone to pay you that dollar?

"Do you know the monthly rent for a studio in that apartment complex across town?  How much salary do you have to earn in order to be able to afford living there, after paying income taxes, food, transportation, etc.?  (Ask him to come up with a balance sheet.)

"Slaves need to be told what to do.  You want to be master of your own life.  One may not be a physical slave but possesses a slave mentality, who acts only in response to the will of others.  Only you can decide what you want to be.

"You are born/growing up here.  You'll do much better than Mom and Dad could ever achieve.  Do you know many kids out there do not have what you have?  You'll be happier if you are more grateful.  You have the freedom and resources to do the things you want to do.  Do not squander it.  Life is measured in time.  Time goes by fast and does not wait for you."