I beleive in the reality of ki. It seems as time goes on I become more and more aware of the ki within and without me.
I remember the first time ki spontaneously manifested in me outside an Aikido context.
I was practicing western style sword fighting. I thrust with my sword, and I felt ki boil in my belly, flow up my body, through my arms, and through my sword into the chest of my opponant. His legs kicked up in the air, and he sailed back several feet. I KNOW I'm not physicly strong enough for that feat, it had to be energy.