most non-religious people attain happiness via intuition instead of education. in other words, secular people tend to become happy as a result of their direct, instant, or non-rationalized sensation of what is causing them to have a positive psychological condition, rather than for religious or educational reasons. if such sensation can be called 'knowledge,' it should be recognized as self-knowledge or a self-conscious state of mind.
in practice, there are several important features to note insofar as this self-knowledge (about oneself being happy) goes:
1/ this knowledge has a physical foundation as it is usually based upon certain sensible objects, and at the same time it has a psychological foundation since it must go through a cognitive process after all;
2/ the knowledge may usually be obtained instantly (as in the case of a religious epiphany), but it can also be attained after a long process (like any quantitative change leading to the eventual qualitative change);
3/ such knowledge can be ephemeral or long-lasting, depending on the extent to which the person can 'control' or use it.
in short, since most non-religious people obtain happiness by way of intuition, it is not only helpful but also necessary to pay attention to whatever sensible object that may lead to such 'naturally-obtained' knowledge.
1/ all people are feeling subjects and, as such, their feeling can be conditioned through active effort.
2/ considering the fact that most religious people become happy through their faith in a holy being, and the fact that most secular people gain happiness by way of intuition, it is theoretically possible to say this: every one can be taught and trained to be happy.
2/ there is much knowledge to learn about happiness in theory, just as there are many techniques or skills that can help people to become happy in practice.