Definitely, but different things for different people. Many in the military probably learned that people at the top didn't appear to know what they were doing. A lot of us probably became more solidified in our view that knowing the history, only a fool would do anything other than ignore Afghanistan.
But the people who learned the most were the ones who earned the most from the experience. There's a lot of money to be made when you contract big parts of a conflict and "nation building", and we've never really done it on this scale before. The big payoff was almost certainly members of congress (personally), the owners of the war for profit gangs, and great landing spots for retired military and DOD personnel who helped direct contracts to the war for profit gangs. This opened a whole new war for profit scheme; where before it was confined to expendables and hardware and you could more or less observe the effectiveness. Now you can blame duds on people who just can't get it instead of faulty hardware.