The circumstances that created both his experience and knowledge base will not precisely repeat, so you are technically correct. But he took what he learned and passed it on to others ensuring that the lessons he picked up the hard way might prove beneficial to following generations. And, following his example, we can do the same, in matters of weaponscraft or otherwise.
There are today some VERY fine young Marines and soldiers instructed by him setting the example of leadership to their troops; some from his own family and many others who are not. Not all are in the military, of course. But enough are that I believe it will be enough to make the difference when it counts.
I can tell you what his parting advice to you would have been: Carry on, and shoot straight. Those were the last five words I heard from him, several years ago.