It is the mark of an educated mind to be able to entertain a thought without accepting it.
Written by Aristotle more than two millenia ago, these words have rung especially true to me lately. Most specifically in that it is possible to be friends with someone I disagree with. Too often today we see people tearing down each other's character because of a difference in opinion, but that is not necessary at all.
Entertain the thought. Consider the what-ifs. Cogitate on the manner of thinking, but without necessarily accepting it yourself. Yes, it is possible, and it sure makes life a lot less stressful!