OLD didn't work for me so I stopped investing time and effort into it. I wouldn't call it a "mistake" necessarily, other than that I probably kept trying longer than I needed to.

Making excuses for other people's bad behavior. For example, they blow off a date or cancel at the last minute and I would immediately be thinking of excuses for them. I stopped doing that; they can explain for themselves and if I don't buy it or simply don't feel particularly empathetic towards their reason, I stop investing. There is too much BS out there to bend over backwards for every little thing.

I am more explicit in my terms. If we're "exclusive" or "dating" or "together", what does that mean? It's going to be a two way conversation until I'm confident we're on the same page. Apparently, "exclusive" to some people means we have sex only with each other unless they feel like sleeping with someone else.