I must say this is an interesting perspective, but I also think sometimes people say they are happy just to feel good about yourself. But they are trying to run away from the truth. It's possible to accept where you are, while in all, balance is the key, like you said avoiding the hard parts can catch up with us in the future. We can just rely on appearance or just our words, but if we are to concentrate on real growth, this requires so much effort.
Most happy people are liars. :)