That I agree.

Happiness in a relationship comes from effort of both sides. Most of problem are caused by one side having good dream/wish, but the other side not responding.

Sigh, sometimes people just set too much barricade in their own life.

Also, I agree with what you said - it's buried in one's nature if he/she is easy to get upset or not. Some people are more sensitive about what other said, or how they acted, or what mood others were in.