I've noticed on the shy days they will have 1 go and thats about it, on the hungry days they will have several goes at the lure if they miss it the first time.
Its a real challenge to crack the code on the hard days, that for me is the beauty of fishing. How frustrating it can be on the some days, and how good it can be on others.
The great reward for me is cracking that code, some days the puzzle is set at hard and others its easy and you never really know until you are out there.