2. The fundementals are the most important

This came to me today and I should have probably saved it for a later date, but I think it's one of the most important rules.

No matter what you're faced with, there are some fundemental concepts at its base.  Whether it is stock investing, weight lifting, physics, car repair, etc... There's some fundemental principals that one must learn first.  They are the foundation that you can depend on.  Once you master the fundementals, you can move on to the more complex, abstract, or unconventional concepts to improve your performance or the outcome.  The reason I say this is simple: when things start going wrong, the fundementals will save you.

In mathematics: if you know your basic concepts, you can solve most complex problems.
In weight lifting: if you're not making progress, keep pushing yourself and stay committed.  You will see results!

I guess the most important thing is this:
Develop your own personal fundemental life principals that you stick by in 99% of cases.  Keep them simple and make sure that they are logical for you.  Ok, so what about the last 1% of cases.  Well, those cases are the challenging ones.  They need more than fundementals.  Sometimes they'll never work out...