Yeh I understand
Its probably just a habit ive picked up from hitting the pads with some gym owner(weight lifting gym what had a few bags) he used to just get me to do the basics and expect me to put full power into the straights.
Also when ever I use the bags (it was like 3-4x a week) I always end up punching them full wack,probably because I had no reason to practice combos and the fact that I just like to use it to revile my stress and use it for cardio.
And it feels good to beat the shit out of things