I'm the guy who made the first catfish comment and I can assure you I'm not a bot. It's my go-to strat early game and thought it was funny. Catfish, protein, muscles, that kind of thing. But then I checked my comment history and noticed it got downvoted all to hell in the past hour and came here to see what that was all about lol
Edit: for the actual strat, one of the first days is guaranteed rain, so down by Marlene's, if you line up all the other stuff in the days prior (meeting townsfolk and all that), grind fishing levels beforehand, you can go down there and try to round up as many catfish as possible to bankroll
I believe it's the 3 am YouTube vids of people fishing out catfish that then shows them where the nearest fish ponds for them to fish other fish and leave the catfish, but that's just my theory could be some country's inside joke or something else