If you could go back and do one thing in your life again

What would that be. 

Good question.

i assume this also means a period of time that you’d like to do again and for me that would be September 2015. Spent a month rock climbing in Yangshuo China between jobs but also prepping for an advanced exam and just spent the morning or the afternoon climbing and the morning or the afternoon studying and then went out in the evening to the bars and restaurants there with people I knew from the language school or the crag.

it was a delightful time

Cuddle each of my children for the first time when they were new born.

For a less corny (but no truer) answer - I wouldn't mind living the 1995-96 academic year again.

"If you could go back and do one thing in your life again"

I actually first read this as "If you could go back and do one thing (different) in your life again"

That would be two women. One when I was 22 and another when i was 27. Not obsess over them. Perhaps I would have taken the ticket from a USMC recruiter in LA. I explained to him that I was not legal in the US. He replied. "That don't matter. Come into the office."

But, if actually asked it would be the six weeks in Mexico. And I did not even get laid.