In his youth my grandfather was a boxer. He taught me how to follow through on a punch by advising “always aim for the back of the skull.” It’s served me well and I think it could be a good metaphor for going all in.
He also taught me to know my limits, though, through his example of declining an offer to box a kangaroo. He said the guy who did was never quite right afterward. The ’40s were a different time, indeed.