Why do most people normally Not feel Qi until they practice Qigong?
Because in the course of normal day to day routines there is no means to increase energy levels beyond what is normally experienced.
It is like a cup that is always filled to half every day and then one day the cup is filled to the brim and it overflows. And there we have Qi sensations!
When this happens, you are in for a very pleasant surprise that will change how you see everything forever!