For me it hits hard when I do that first set and I think to myself, "Oh man, this is just 1 set...I have 15 more to go" or whatever. That's when the dread feeling sets in, but it last usually only for a moment or two then I don't even think about it any more. I think about the 2nd or 3rd exercise I see the pump, I feel the work being done, and I really begin to enjoy my workout.