Its all very subjective. One persons calling of light/moderate/sever may be significantly different to anothers.
I have only had sever once. South of the Alps at 38K and it was like running into a brick wall that suddenly fell apart and started bashing the aircraft, it was noisy, the vibration frightening and i couldn't read any instruments or grab any of the AP controls on the FCU. We descended to 21K to get out of it but then with the Alps looming, we had to climb back into it! Fortunately it had died down.
Not a nice experience!