Maybe you're reading too much into it. Maybe its derived from some sort of water travel saying...like say, back when it was fashionable to travel by boat, a salty sea captain and his crew made a boat out of peanut brittle. And everyone told him that it wouldn't work and they exiled him from the town and in his escape from the swarm of angry villagers his peanut brittle boat sailed far enough for him to make his escape.

Peanut brittle...that's what floats my boat.