No wonder you think so much. I think that movement in particular has the effect of increasing the intensity of whatever mood you're in. Happy? It's so beautiful you'll smile for ages. Sad? It'll make you cry. Maybe you should stay away from such potent stuff while orienteering. ;-)
I'm not sure if the affinity for Rach 2 causes the thinking or is a consequence of it. While symphonies are generally my favorite classical works, I am fond of many piano concertos - Tchaik 1, Rach 2, the Grieg, Prokofiev 3, and Beethoven 4 and 5. I haven't heard many; I may do a broad study on piano concertos in the future.
In the interim, I will enjoy my late romantics. Apparently while I orienteer. The music player in my head only sometimes takes requests; usually it's on "slow random walk."