Earlier quoted context omitted.
Trying to convince yourself you're not a victim also leads to weird mental twists, like concluding you're where you are by choice and reframe your situation as some success to not look like a loser. Accepting you're being fucked is the first step to get out of it.
Munger didn't say that you should deny being a victim. You should just not use that situation as an excuse for your future actions. Anyone can be victim of anything. But what you choose to do after that experience is the key.
"If you just take the attitude that, however bad it is in anyway, it’s always your fault and you just fix it as best you can – the so-called ‘iron prescription’ – I think that really works."
...does not work for e.g. victims of child abuse. Child abuse is never the fault of the child.