We all feel this way. If your former spopuse was cheap, never on time and thoughtless before the divorce, he or she will continue to be right, late and say stupid things in the divorce. The things that you tolerated in marriage under the perfume of love will infuriate you in divorce. You have to learn to accept, overlook and forgive or else you are going to expend a lot of wasted emotions on someone you're not even married to. You can only be angry or hate someone you care about.
Different values is really the operational word here.
No one else has a clue. Approaching your ex first with a friendly word at such events puts everyone else at ease and it is worthwhile practice. We still connect over our now-adult kids and see each other at family functions. I'm proud that we've been able to happily share family life-milestones together without it being painful to be together. It's next to impossible to skip this one through.