My favourite example of this, is as Ksynwa mentioned in their comment, people who try to read theory - or who entirely avoid reading theory, and instead to become communist via memes or communities - but never keep up with the theory they’re trying to read. So they end up learning nothing, but don’t have the frame of mind to identify that they didn’t get anything from theory because you can’t simply read it, you have to ponder and argue it too. You have to live the revolution, not just fantasize about it. Those of us who have read theory, have pondered it, and have argued it are living the revolution, that’s what makes us communists.

If you do not live the revolution, you could not possibly defend the revolution with your whole heart. Communists who don’t read theory (or, at the minimum have theory explained to them and take an active approach to learn it) are just setting themselves up to become counter-revolutionary.

You can try to be a forklift operator, you can spend weeks or months on it. But if you never learn how to operate a forklift in that time, you were never a forklift operator.