IMO It isn't a waist of time if you try to figure out what didn't work and why. I.E. You mentioned the drop rate affecting mackerel hook-ups. When I don't want mackerel, they seem to be Easy to catch, when I want them(for sharking, etc.) they're scarce. This might be because when I'm after them for bait, I'm rushing so I can get to "real fishing".

Tight lines,
Wade