I am living here and now. The blessing of my life is that I am totally concentrating on the present moment. And I want to be because there is nothing but the present moment.
We start to realize that there are anodynes in life that help us through the day. I don't care if it's a walk in the park, a look out the window, a good bubble bath - whatever. Even a meal you like, or a friend you want to call. That helps us solve all this stuff in our head.
But like infection is the petty thought: it creeps and hides, and wants to be nowhere--until the whole body is decayed and withered by the petty infection... Thus spoke Zarathustra.
You will never get to the irreducible definition of anything because you will never be able to explain why you want to explain, and so on. The system will gobble itself up.