It just brings bad luck, whether related to fishing or not.
My buddy wanted to bring a couple banana's in my boat a couple weeks ago and I actually told him either eat them before we get on the boat, or leave them in the truck. He ate them before we went out. Now that I think of it I think it still brought us bad luck, well him more than me as I caught 2 pickerel (which we were targetting) and he didn't catch any. Meanwhile we were using the same bait, although he did catch other types of fish. Another thing, I lost alot of fish that day, atleast 5-6, some of which were nice ones. Could of just been a coinsidence but you never know. Funny aint it? Leave your bananas at home, and dont even think about them . Their not the greatest for you anyway, they take longer to digest.