Happiness is not a continuation of pleasant sensations (totally impossible), but rather a content state of being with your life as it is in the present.
Kids don't make us happy in themselves, but acting like one can be a step in the right direction towards that end. Children are more content, less judgmental, and usually live in the present -- all ingredients that will lead to contentment (aka "happiness"). We, as adults, need to do the same, even though we'll have to spend lots of time ridding ourselves of these layers upon layers of "grown-up" illusions.
Some people are a bit more content than others naturally, but even these folks trick themselves into thinking they're happier than what they really are. Happy just doesn't come easy -- plain and simple.
Who's happy? Well, for one, Yongey Mingyur Rinpoche is a happy creature, but he's worked extremely hard to become just that -- happy! Another one who comes to mind is the Catholic nun Bridge McKenna. Again, it's not magic, as she's spent her whole life on achieving this end, and now she's "happily" there. You see, they bypass the world's definition and travel the true road to peace. And that's a sacrifice (yes, happiness is a sacrifice - how ironic!).
I became aware I breathed a beautiful breath given to me by my god, and then I knew I was free.:wink: