What's an opinion you've changed your mind about recently? Why?

I guess it depends on how you define "recently". But my views on many things have evolved over the course of my life. When I was a teenager, for example, I bought into the whole "Drugs are evil, and drug dealers are worse than murders or rapists and should get the death penalty" mindset that was prevalent in my area. Now I'm a Libertarian who holds that all transactions between consenting adults are inherently legal because no one else has standing to say otherwise, I consider the State an invalid construct, and I think you should be able to imbibe, inject, or ingest anything into your body that you want. I further believe that anybody in jail for any non-violent crimes related to drug possession, distribution, consumption should be freed immediately.

I'm also completely opposed to the Death Penalty these days.

I take Climate Change more seriously than I did when I was younger. I have come to believe strongly in anthropogenic global warming caused by greenhouse gas emissions, where when I was younger I maintained a little bit more skepticism about that.

I better understand the idea of systemic racism now, and am much more understanding of (some of) the challenges faced by people who aren't White.

All of those things have been things where my understanding and opinion have changed over a period of years though. There wasn't one specific day where I just woke up and had an epiphany and realized "Oh shit, was wrong about $WHATEVER."