My Marathon Truths
1. 26.2 miles is hard. I don't care how much you train, how well you are prepared, and how many times you've done it before. 26.2 miles is a long ways, and always a physical challenge for the body. Celebrate *every* finish line.
2. You can't plan for everything. You may know the course, have the perfect nutrition plan, have all the right gear, etc... but I guarantee something that you didn't plan for will happen. It's all about how you deal with the unexpected.
3. Nutrition is crucial. I've heard it preached for years, and I've gone haphazardly about it for those years. Practicing and getting the plan right for race day is really crucial. You can't make it 26.2 miles on a pre-race banana and water. (With that said, know what's available on the course...)
4. A positive attitude will get you to the finish line. Heavy legs are an obstacle, but a negative attitude can be a game-ender. Keeping a positive outlook (and this means accepting what you are able to give at that moment even if it doesn't meet you pre-conceived goals) can push you through those last miles.
5. Goals are fantastic, but they don't define your success. That sounds counter-intuitive, because the point of goals is typically to help specify what means "success". But I'm only talking about time goals in relation to the marathon. Success is crossing the finish line feeling like you did what you could with what the day/course/body had to offer. There is always another day and another race.