Fishing Secret

A guy is out fishing on a cold morning...

...and he is not having much luck. Well, down the dock he notices an old man who is doing great, just reeling in fish after fish. He goes over and asks the old man what's his secret. The old man just mumbles something incoherent. The younger man leans in, "I'm sorry, what?" The old man mumbles again, this time a bit louder. "I'm sorry, I still didn't understand you." The old man turns his back, spits a wad into his hand, turns back and says, "You have to keep your worms warm."