I've started meditating a bit and I think I understand it a little. It's not that you should be in the present moment as in focusing on your current state and all the details of your current state. It's a state that's divorced from all the details of your life right now. You forget your sex (i.e. gender), your name, your race, age, etc., and your life situation, and you sort of just experience being. Try just sitting in a chair staring at a wall and just experience your breath and the feeling that at this moment you're a consciousness that exists, nothing more. Sometimes to ground myself, I remind myself that everything is passing, and that this is just a very small part of existence, and that not only will my feelings eventually pass, but one day I'll be gone too. In that moment of feeling very small and insignificant, I have some glimmer of a bigger picture, and the things that are causing me pain are also diminished.