America's military allow the rest of us to do what we do.

College didn't stick, so I worked odd jobs, but I've always written songs and played music. I actually met a guy who was a songwriter, which I didn't realize was a real job.

I moved to Nashville to be a songwriter. I found out that was a job, that someone would pay you to sit in a room with a guitar and make up songs! It is the greatest job in the world. I wrote three or four songs a day. That's what I lived for.

I didn't know they would pay you money to sit in a room and write songs for other people. I always thought that George Strait was singing a song, he made it up, and that was the end of it. But the instant I found that out, that that could be a job, I thought, 'That's the job for me. I gotta figure out how to do that.'

The search for happiness has long been a dominant feature of American life. It's a byproduct of prosperity, not to mention the most famous line in the Declaration of Independence.

I've discovered the joys of happiness.

I think my capacity to change has given me tremendous happiness, because who I am today I am completely content to be.

Few men in their 70s looked as good as my father did. What was his secret? Genes, maybe, since he didn't exercise or diet, and he kept a candy drawer, drank a pot of black coffee every day, and read in the middle of the night. Still, he took such joy in being a dad - and in life in general - and his happiness showed.