How to make the week fly by

I can not believe just how fast this week has flown by. It seems like it was Monday just yesterday and now its Saturday afternoon already. How is it that some weeks drag on and on and others fly by; and in both cases one could be swamped with work? Is it just how much one enjoys the work one is doing, or if one is more productive one week than the other, or if makes more money one week than another? Lots of combinations and permutations to come up with the perfect recipe of a work week flying by and being productive and having fun and making pots of money!!