Dating a single parent can be a lot like struggling with a toddler. They punch you in the eye, spill juice in your bed, and say, "I love you SOOO much."
Love your kids with everything you've got. Let go of your ex, as best you can, and focus on the impact your love is having on your kids. Stay true to that value and you will always choose the high road.
When working through the details of our parenting plan, she played the "family law" trump card and let me know I would not be getting 50/50 parenting, because if she went to court she knew she would win exactly what she wanted.
I'm a serial monogamist because I'm hoping to find the next relationship at some point. And that point in the future is very flexible in terms of time, and even in terms of what the person or the relationship looks and feels like.