I can now say with some confidence that I have my marathon racing dialed in. It took a long time, but I finally did it. I know how to prepare for and race a marathon. I also think I can do better than 3:22:21 and 3:15 is in the cards. However, I am not sure I will as it would require more running and running is not exactly my thing.
I did well this time, no injuries other than some minor cramping near the end (i.e. I need more preparation to hold 8 mph), and a new blood blister on my toe. My shoes have pretty much had it. I am not sure how many miles I have run in them, but certainly a lot more than manufacturers recommend. But then again, manufacturers are in the business of selling new shoes and you don't sell new shoes unless people retire their old shoes.
I will spend some time to write some posts that go into detail about what I learned but I can start by saying that the learning was mostly of the "unlearning" type. I.e. whatever people recommend, don't listen to it. It was only when I stopped listening that I started to do better. 15-20 minutes better, no small potatoes either! And it holds up the way it should, i.e. I can repeat it. It is not a one-time fluke.
I can now routinely run a 3:25 plus or minus, instead of a 3:40 plus or minus. I am faster and I feel better. I made an even bigger gain in my Ironman marathons. There the gains are well in excess of 20 minutes.
Another thing that makes it real is that I am getting older. I am past 50 and apparently past 50 you can't improve anymore. Whoever said that is full of s..t too, although it is certainly harder to improve past age 50 than it is for say a 20 year old.