Im sorry, pardon my ignorance but I didnt read that as "No having fun in Church". Sorry. Not trying to be confrontational, just debate the fact that God wants us to sit quietly absent of outward joy of his presence. But if you are Catholic then you believe that the Mass is a re-presentation of the sacrifice of Him. I cannot imagine being at the foot of the cross on that day and "having fun".
Being at a properly said Mass is joy - the awed joy of being in His presence - not the hand-clapping kind of joy that we experience at a baseball game or a concert or a sschool play.
We celebrate Gods sacrifice and Jesus' revival...not his death. Hence the joy. Lets think back to the disciples reaction to the Lord. He has risen and Oh what a fantastic time!