The difference between pros and fish is that pros think about what they do, so if they make some weird play with a weaker hand, they will always be able to tell the reason why. Fish don't and are very luck dependant. They also are results oriented, can't say I'm not though... I thought that the term fishing meant that regs were fishing for the fishes stacks.
If suckouts and bad beats didn't exist, we wouldn't have fish in Poker. I had times where my opponents called me a fish for disobeying pot odds
, hitting my hand and stacking them. Last hand was when villain made a pot bet with 8BB and I called with nut flush in position on a queen high board. Spade on the turn, he keeps barelling and I call. River is a blank and I'm holding the nuts, he bets the river, I raise and he stacks off himself. Shows QJ spades.
A donkey is someone who shoves with the worst hand like a flush or a straight draw and plays bad Poker. Also donk betting is leading into the previous street aggressor.