Ability to Compromise
There are subtle changes that most people can make in their lives in order to make their spouse happy. This is part of the never ending compromise phase that is critical.
When single, I’d watch football games at bars every Saturday and Sunday (and sometimes Thursday). Once married, I toned it down to one day. This is a manageable change that I was willing to make. However, had my wife insisted that I give up all sports entirely, I would have resisted and eventually resented her. That resent would have spread and ultimately influenced my overall attitude towards her.
The same is true for just about everything. The willingness of the other person to compromise today (of the lack thereof) and your reaction to it will prove to be a precedent setting event. If someone is absolutely unwilling to compromise on minor issues, you should expect the same for larger issues. Don’t be shocked and appalled by it when it happens three years from now- you knew this going in and you accepted it