It could be from personal life experience, a reddit comment, movie scene, or chapter in an autobiography book, etc. Anything that made you think, "Ya know, maybe I don't have all the answers."

My personal example: I lean more towards Redpiller philosophy, so I was always more sympathetic towards the bros. However, I had a lady friend (we will call her Sarah) who once had a "kind/loving ex-boyfriend." This particular ex-boyfriend of hers did all the right things. He made good money, was funny, handsome, and treated her right. But he wasn't much of a fighter. He was physically weak, not his fault. Not everyone's a fighter. But Sarah was brutally beaten and almost raped because of the fact that her man couldn't defend her. He tried, but he just didn't have it in him. He didn't have that killer instinct to take on a dangerous perpetrator. The neighbors came to her rescue just in time, and their relationship was never the same after that. She (unintentionally) looked at him as the man who couldn't protect her. She didn't want to see him as weak, but her mind could not shake off the incident. Her dating preferences after that leaned more towards "stronger/masculine" men. She was no longer attracted to sweet/handsome men anymore. The "handsome" part no longer is a priority for her, just a bonus.

Now I kinda understand why women go for guys who have more aggressive personalities. It's a safety net. I may not fully agree with it, but I get it. I've heard women say they like a badboy who's a jerk to everyone else but nice to her. I'm wondering if that's more to do with wanting to be protected, rather than wanting someone who's "fun."