It may sound harsh but here is how I handled it when it all had to be 'fair' when my daughter was about 5 or so. Your mileage may vary (I am not tall) but adjust to fit...
I told her:-
Life isn't fair - I wanted to be taller
It stopped.
I don't quite see this working for too many gifted kids. For the same reasons these kids get into trouble at school and other places. They don't just take simple answers as a given. They want answers that make sense to them. At least mine would blow up over this. He needs to reason about things so he can understand them. Once he understands, he's fine.
