I know because I've grown and learned from every choice, and every mistake I've made in the past. I think it sums it up well when I mentioned earlier that my boo makes me want to be better for both of us. Also, I never saw a family with my previous. I thought at the time, I just didn't want kids in general. I was a firm believer in that. Looking back, I just didn't want kids with him. I didn't view him as being the best father, even though his father was and he had a great example in him. My current man is going to be an amazing, loving father if we're blessed with children. My previous, I took marriage as the next logical step because we were together for so long. That was my mistake.
Hindsight is 20/20.
Do I think about them? No. They come in mind with certain memories, but it's part of my past.
It's not just a switch. I spent so much time having feelings over my previous. It was an emotional rollercoaster, but all of that is over. We've both moved on, and I feel like I'm finally with the person that fulfills me on EVERY level, which I've never had before. I also know it's reciprocated, he shows me every day. I'm truly blessed.
TL;DR you live, you love, you learn.