My 20-year-old son just moved into a fraternity house at his college in the US. Last month, I spent three days there trying to turn his bedroom from a fluorescent-lit hellhole into a page from an Ikea catalogue, and while making up flat-packs, we discussed his hopes and plans for the next three years … what he wanted from life, from love, his strengths, his fears, and how to approach his college years so that he could set himself up for a life well lived. On the final evening, I found myself alone in a horrid Illinois hotel, still thinking about my boy’s apprehensions for his journey into adulthood and how I might help him make decisions he would never regret.

I went to Twitter and typed: “What is your biggest regret. Asking for a friend.” The response was huge. It wasn’t just big in volume – more than 300 replies – but the tweets were devastatingly honest. I had casually asked a question that, surprisingly, a lot of people really wanted to answer. These were sad, sobering, enlightening responses – big stories told in 140 words to a stranger on a Saturday night. I don’t know why so many people had such strong regrets living so close to the surface – but by the end of the evening, I felt I might have learned more about life through what people regretted not doing, than through 55 years of being given advice about what to do. I’m clearly no authority on this subject, but I’d love to tell you a bit of what I saw that night.