Something that's been on my mind lately is..the truth. (Sounds scandalous, right? Now that I've caught your attention...)
Last year I had the opportunity to attend the evening classes at BYU's Education Week. There was this one particular class that I particularly loved that I would particularly like to take again. I can't remember the title of the class, but it was about not worrying/facing life/dealing with problems gracefully, etc.
On one of the class days we talked about what truth is and how it "will set you free." Besides this scriptural reference (John 8:32), the Lord gives us an actual definition of truth in Doctrine and Covenants 93:And atruth is bknowledge of things as they are, and as they were, and as they are to come."
So the truth is knowing things as they are. That means that you need to get rid of all of the "shoulds" in your life, like "I should be as thin as that girl who looks like she has virtually no thighs," or "I should have a boyfriend," or "I should be smarter" etc. Look at the areas in your life that you're unhappy with right now. If you think about it, those problems can probably point back to a "should" or "shouldn't". Welp, that's just not the way things are. Once you stop connecting the way things should be in your mind and the way things really are right now--the truth--then the truth will set you free.
Just a little nugget of wisdom that I need to remember the most right now.