Up until a year and a half ago, I had never enjoyed a jog in my life. I had done plenty of "jogging" during school years, as part of gym class, but nobody had ever explained to me difference between a pleasant jog and running until you drop.
I stopped exercising for many years. Then started powerlifting. A couple of years ago I decided that I should take a walk every day. Then that I should do at least 10.000 steps a day. A year and a half ago, I figured I could probably do a very light run. I enjoyed it. Then I started running at least every other day (during summer). Stoppped during winter. Picked it up again last spring. Now I'm again awaiting spring.
It took 41 years of my life before I realized what a light run was. I think most people don't run because they have never actually learned what a light run is. It's always flat out.