"I don't get many things right the first time in fact i am told that a lot"
I think he has had many relationships in the past, where he has screwed them up, and he thinks many people see him as a failure in aspects of his life.
"Now I know all the wrong turns, the stumbles and falls
Brought me here"
He's expressing how now he can see how all the relationship failures he has had in the past that then seemed so important, brought him to where he is now and how happy he is.
The chorus is him just saying that he is the luckiest person to have who he has.
The next verse i'm not quite sure on, i'm guessing he's saying that he had seen her before and it never crossed his mind, and if he had known what he knows now, he wouldn't have wasted all the time on the girls that didn't really matter. The third verse is him telling a story of an older man who he looked up to and wanted to be like someday with his wife. I'm guessing he could see that being them someday and that's why he said " I'm sorry, I know that's a strange way to tell you that I know we belong" And that he is a little bit strange in how he expresses himself but he wants to tell her things that are true that mean the most to him, and not cheesy lines.
