When I was a brand-new Platoon Leader my unit deployed to Panama for Jungle Training. We did a mission where the bad guys (OPFOR) engaged us. In the midst of this, I found myself shooting away with my radio operator and running through the jungle having a bit too much fun!
At the end, my Platoon Sergeant (guy really in charge of the platoon) and pulled me aside. He said "Sir, I'm going to take away your bullets". Of course, I asked "What do you mean, why would you do that?" His reply was "You are the PL, you should be maneuvering the squads, positioning the machine guns and calling in artillery fire, not shooting your rifle. We have plenty of guys to do that and they are better at it than you are"
I was of course deflated. Here I thought I had done pretty good during that fight, and I found out I hadn't done anything right at all!
His feedback, while brutal, was some of the best advice I've ever received. It made the following so painfully clear!