I will also add that as a leftist, you need to learn the skill of de-radicalizing yourself, because at some point you WILL get hit with truly 100 percent believable propaganda, get pulled down a rabbit hole that's at best a self-righteous dead end cause and at worst connecting to the far-right pipeline based on shared hates, you WILL get scammed by a grifter or someone who is using you, etcetera. I've personally been there and done that more than once and each time has been an albeit painful learning experience for me.
Bad people exist on our side or can sneak into it with the right language. People can uptake awful ideas and internalize them. This includes outright predators (just look at Cesar Chavez for example, or Hakim Bey, or that guy that led the PSL). This includes engagement grifters who learned that rage and fear = clicks, and state propagandists from everywhere in the world (if you think the US is the ONLY propaganda machine, you'll be sadly disappointed and likely drawn in by whoever has the loudest and most strident propaganda against it). This includes people who've let their ethics/morals be determined by community vibe rather than a nuanced understanding of how the issue affects your own ethical principles and if it even does. This even can include you, yourself.
You need to be able to step back, look at yourself, look at the people you've found yourself surrounded with and be "this is too much, this has gone too far, this is ridiculous, this reminds me of a cult/the far right/whatever, and most importantly, this is hurting actual people, not just an abstract wider harm or making someone feel Offended." You also have to develop the skillset of abandoning binary thinking and going both "you are 95 percent correct but 5 percent wrong, but I can overlook that five percent because it's a nonissue in a wider perspective" and "you are 95 percent correct, but you are actively spreading bigotry/disinformation or doing harm on a personal level, and that is an absolute dealbreaker even if you're correct."
And you have to be capable of doing this even if it can make you lose said friends, even if it can make you seen as a pariah, even if it hurts to feel like you're the only wrong one, you're the shitlib/lazy person/wrong while everyone else is the True And Pure and Correct Way you just can't live up to (in fact, these feelings or this actually happening is a screaming red flag that you NEED to pay attention to)
You also need to try to keep friends who DON'T all agree on That One Issue or who like you for you as a person and not just what you can do for them, because that makes leaving an abusive situation or being misled easier.
If your entire leftist experience is ONLY one specific community (especially a hyperspecific one of "we're the BESTEST and MOST CORRECT") WIDEN THAT EXPERIENCE yesterday. Get to actually know leftists who are "lesser" in your mind not as conversion projects but to see why they AREN'T all sold on (for example) a specific form of theory, why anyone who does/doesn't subscribe to a specific view of the body/nature/how one interacts with it, does or doesn't like a specific media or art style, what the most urgent issue is, or literally any other internal culture war issue that feels like the be-all-and-end-all issue thinks the way they do without judgment.
This is important for staying grounded for two reasons: it provides you with a community on which you can fall if you, on evaluating the issue yourself, decide you're out of step with your group/friends/online circle and do find yourself Rejected and it also reminds you that we are all human beings with both limited knowledge and yet wide, varied lived experience. That you CAN be wrong and that is okay, that changing your mind isn't a sign of weakness but of getting better information or a wider perspective, etc.
