When our kids were little and I was traveling on business a lot, my wife scolded me for not spending enough time with the kids: "If you want them to WANT to visit you in the nursing home, you have to invest the time NOW to build relationships with them -- if you wait till YOU have time, it'll be too late."
It reminds me of a point of view of one of Thich Nhat Hanh's friends, mentioned in his book "The Miracle of Mindfulness".
The gist of it was his friend was discussing spending time with his kids. He would view something like the concert Patterico mentioned as "his time" and sitting in the car with a crying baby as "the kid's time". He simply decided to start viewing "the kid's time" as "his time", he was choosing to spend quality time with his children.
Often times when faced with what seems like an important decision, I ask myself "What is this going to matter in ten years?" It's not always going to make decisions easier, but the added weight and long-term outlook do put things into a better perspective.
Some people will always regret whatever it is that they decided not to do. The best defense is to make mindful decisions. It's not surprising that the thing this guy thought he really wanted to do is something that is force fed to us 24/7 by the media. Last time I went to a concert I was thoroughly bored. But I'm rambling..
It's a good point, but at the same time it's important to remember that the point is to have gratitude for the present moment, rather than to get caught up in the imaginary future time from which you look backwards.
"So live as if your were living already for the second time and as if you had acted the first time as wrongly as your are about to act now." - Viktor Frankl