I believe it's true what Ayn Rand teaches (or at least what I think she teaches). And that is that man seeks above all else his own self interest.
I was driving around Long Beach, CA the other day and I realized that everyone, and I mean everyone, pursues happiness as their ultimate goal. Whatever is done, it's done for the sole purpose of individual happiness. Every single thing. From the tiniest breath, to even enduring extreme pain, it's ultimately for our own happiness.
I'll take it even further and say altruism is ultimately selfish. I'll let the reader think about this.
Even alcohol, cigarettes and drug abuse. It's all about happiness.
It's the mature person though that can look long term and deny short term pleasure. By denying short term pleasure, even enduring short term pain, in the long run will reap daily dividends.
In fact, if someone was to learn what makes them happy, what truly makes them happy, could save enough and never have to work again the rest of their life by the age of 30. Once "enough" can be well defined, "enough" is not nearly as much as we currently think it is.
What can be more important than the breath we just breathed or the beautiful sunshine?
There's so much to be thankful for. I'm thankful for my material things, but I'm thankful for so much beyond that. Gratitude should be a natural outcropping of this great life we have the pleasure to live.