Similar pipeline here. Hanging around in all the I suppose you could call them “utopian left” spaces and being patted on the head “you’ll wise up when you’re older” followed by a “refutation” of whatever I suggested that itself demonstrated that they hadn’t actually listened to a word I said. Even some ideas I explored by advocating for them and later decided were flawed, it still burns me that people who otherwise accepted me as a reasonably intelligent person would take an idea I shared with them so lightly as to not listen. That primed me for the “if you aren’t going to participate constructively in good faith then you can fuck off” space that was CTH