Abusive ex, nothing physical but emotional / co-ercive. His style was to furiously accuse me of doing something wrong, and then to keep laying into me aggressively about why I'd done it, how disrespectful it was, how angry he was, demanding an apology, how was I going to make it better, and so on. If I tried to defend myself, he go harder, often telling me loudly and angrily that he wasn't angry, he was just 'trying to understand' (reader, he was not). Most of the time, what he was whaling on me about was subjective - that I'd hurt his friend's feelings, that I didn't take the recycling out enough, and so on. I knew something was off - he was often messier than I was - but I had it ground into me by his certainty and anger that I was the problem; also he always told me that he knew me better than anyone else so of course he was right.
A while after we separated, we had to meet to sort out some practical stuff. Very objective stuff - numbers, paper trail, and it was all stuff I knew by heart. He got angry again with me about part of it and started up in the usual way, jabbing his finger at me, speaking forcefully, except this time it didn't work. He'd never heard of this thing - except I had an email trail showing he'd heard of it 2 years ago; well yeah, but we couldn't have spent the money on that - except here were the actual receipts. He was just trying to understand - understand what, everything's already here in writing. And suddenly I realised - he wasn't right. He'd never been right. I'd mistaken his force and certainty for being right, but it was just bullshit and bluster. It was incredible. It was like seeing in colour, or realising that the people in films are just actors.
I'd already had a bunch of smaller epiphanies since we split about how I'd always been stressed and walking on eggshells in his company, how much he'd lied to me whilst we were together. I still get anxious and a pounding heart when I see his name. But that was a proper 'man behind the curtain' moment which has gone a long way to helping me move on.