How long you spent on it.
How hard it was to implement.
How clean your architecture is.
How extensible it is.
How well it runs on your machine.
How great it will be once all their friends are on it.
How amazing the next version will be.
Whose fault the problems are.
What you think they should be interested in.
What you expected.
What you were promised.
How important this is to you.
I have to keep relearning these lessons. Finding an experience that people love is far more precious and rare than most of us realize.