Why is it when I play with the piano I get teary eyed?

I haven't learned piano yet, but I do sometimes fiddle around with it and If I'm lucky I form melodies and often times I get this almost teary feeling. I'm confused whether it is purely psychological(like its sub-consciously reminding me of a deep scarred past that I don't remember LOL) or a sign that tells me that I'll really enjoy learning it. I don't get the same feeling when playing my guitar and I've been playing for 6 years even if I do play rather mellow,sentimental or inspiring pieces.