Reasonable expectations. Everyone has them. Some are aware that their own expectations may differ from the expectations of someone else. Some are further aware that how they define "reasonable" may not be how someone else defines it. Those who acknowledge that these differences exist can more easily themselves coexist. Who are these people? They are the politically/sexually/religiously agnostic - people who do not ascribe to any particular political party, sexual morality, or path to enlightenment/salvation. While many may fall under one or two of those, there are very few people in the world who have shed themselves of all three. Very few because almost everyone at some point has something that they believe in. Even self-proclaimed `agents of chaos` are more or less aligned with certain political ideologies, much as politically-void sexual deviants may ascribe to a belief in their god. Everyone has something in which they believe, that being the thing on which they will not waver. Their principles.
Religious denominations fragment and form because they believe their interpretation is more accurate than any other denomination in the entire world. Adopted sexual behavior from worldwide sacred texts is often followed strictly by even the most close-minded atheists. Political parties thrive upon the idea that theirs are more reasonable than the other guy's. Each and every one vying for membership into exclusivity whose goal is to separate and divide. Collective individualism should be based upon unique personalities within an inclusion of diverse ideologies - not segregation.
Reasonable expectations. Everyone has them. Some judge others because those expectations may differ from their own. It never even registers that someone else may have different expectations. They are very confused when someone acts contrary to those expectations with no thought they might be acting exactly in accordance to their own. Or perhaps they may define "reasonable" differently even if the expectations were to line up perfectly otherwise. Those who never consider that other people may act according to opposing motivations are far more likely to assume others are behaving irrationally.
Society is built upon immediate and simultaneous series of assumptions - it has to be in order to operate. Its what creates efficiency and maintains momentum. Every person who is a part of society successfully fulfills their daily role though a majority of assumptions. They assume by getting dressed that culture hadn't decided overnight to forgo clothing, and they assume by getting in their car that roads still exist. Routine is entirely constructed from assumptions. It would be absurd to suggest that we need evidence for everything we are told or to not assume everything we've learned to be true has changed each time it is experienced.
Assuming someone is behaving irrationally however, just because they're operating under a different set of motivations is the very strike of the match which lights the fuse of intolerance. Those who are wholly agnostic rarely proclaim their tolerance by shouting it out in the streets as the Pharisees did, for all to see - they don't have to - they're not at odds with a rival alignment in fear of being judged. Yet in a wonderfully orchestrated life-choice of fail, many others do attempt to illustrate how exceptionally close-minded they are by doing just that. Its not okay to pay lip service to it while believing otherwise - that's veiled bigotry - deceit. It is, however entirely acceptable to not agree with those who's opinions differ. Disagreeing is healthy. When done properly, it can reinforce one's own belief, opens the mind to new possibilities, and strengthens humanity through dialog. Pretending to be something by the light of day which manifests itself otherwise behind closed doors is, depending upon the motivation behind it, reprehensible. And they are suddenly transformed into the very thing they despise were someone else to judge them with the same aplomb.
Choose instead to voice your disagreement. Those who do will slowly become better people, and a population of better people will make the world a better place.