Fickle Relationships!

Why are all relationships,including something as universal as friendship, so demanding?
What is it about relationships that the individuals concerned tend to overlook the simple things and instead start to critically dissect every casual action?

These are ramblings of a confused mind, but at the same time something that almost everybody has gone through.

People meet each other,strike a chord and then carry their relation to a new level. And that's precisely when things start going awry. Demands increase, expectations increase, jealousy sets in. Why does this happen? Why do we ever have expectations from anybody?

Two people enjoy each other's company, have fun together, help each other when the need arises.....what else is needed to be friends? Why should we demand complete transparency in a relation? As long as we know we can count on the other person, why should we ask for more?

Diffrent people think differently on these issues....as for me I guess having fun with someone, respecting the other person's views and trust is enough...wouldn't really care for the nitty gritties