I first heard this in second year university, when my profs started each class with a musical selection. I stumbled into class a few minutes late (not my habit, I assure you), and the music was already playing, pouring out and filling the small lecture hall. Totally stunned me. Oscar Peterson was a genius, which I knew already, but it really hit me hard that time.
Whenever I'm stressed, sad, joyful, or emotional in some way I end up shuffling back to this piece, among others. Speechless.