To finish off this brief emendation then, I'd like to share a verse from Ecclesiastes, which was expounded to me by John Ferguson during his sermons series on Ecclesiastes, and which I think fits well what Piper is getting at:
"There is nothing better for a person than that he should eat and drink and find enjoyment in his toil. This also, I saw, is from the hand of God, for apart from his who can eat or who can have enjoyment? For to the one who pleases him God has given wisdom and knowledge and joy, but to the sinner he has given the business of gathering and collecting, only to give to one who pleases God." Ecclesiastes 2:24-26
So to the one who finds joy in Christ shall more joy be given, but to the one who pursues joy apart from Christ that gain shall also be given to the one whose joy is in Christ. There is no enjoyment that is not given by God. All the pleasures of sin are far from joy, but are merely the fleeting sensations of the self before it is cast into destruction.