It is interesting how we tend to be (if at all) grateful towards other, but ourselves.

With this modern lifestyle, we rarely get the chance to dedicate a moment to ourselves

It made me wonder...
I was told once that before complaining for not having shoes, we should think of those who have no feet. I try to keep that in mind every time I feel disgruntled and regretful.

thank god, thank every god there ever was or ever will be, nature, universe, or anything that is of any value to you, that you, of all the phenomenon in this world, had this rare chance to exist and observe all of this, to feel… to love… to live.

I like your approach. I think that the very idea of God, the monotheist/Christian/Muslim/Jewish god that has been imposed by history and politics ends up ruining the spiritual experience most people could have. The great expectations raised by holy books collide with the cruel reality of a world that seems to have been left at its own devices by whoever made it (and even that is put under scrutiny when people think about all mighty power vs. almighty disregard--free will?).

Ungratefulness, i think comes from the inability to reconcile expectations with results. Religions tend to create lots of unreasonable expectations (justice, for instance).

So, the idea of thankfulness regardless of deity or with a more open gamut of possibilities offers more possibilities for the disgruntled hearts.