I’m not sure I know what this means. I read a lot of British literature and it seems like “punters” can mean either people in little boats or just people walking on a path. No, I’m not going to bother looking it up.
There was a mockingbird in our backyard recently that had an amazingly varied repertoire. I just got thinking about them mocking us, and hence came this cartoon.
As a child I used to tell this joke and had no idea what it meant. The same can be said for many other jokes I told. Some of them I’m not even embarrassed by now!