We are, of course, eavesdropping on TV characters. Their sons Beaver and Wally were played by Jerry Mathers and Tony Dow. And Wally's annoying best friend Eddie was played with uncanny authenticity by Ken Osmond. There was one on every block. I think that's probably one of the major contributing factors to the character's popularity today.
Actors often relish the opportunity to play an unsympathetic character.
But that plus was lost on the young Osmond. Apparently, the character was popular and they brought him back. The metamorphosis is something Osmond doesn't recall noticing. I can now. I watch them now, and I can definitely see the difference.