Fifty
I hit 51 next month, and that's ... well.<p>These decadal anniversaries seem to get more onerous each time. 20? No problem, it just means you're not a teenager any more! 30? Okay, you're officially a grownup, but you can still party! 40 was pause for concern, but it isn't what it used to be, the threshold of middle age: that's 50. Oops ...<p>Well, as Terry Pratchett observed, inside every old man there's an eight year old wondering what just happened. I don't feel <i>emotionally</i> middle-aged. But my knees creak in the morning, I've survived medical conditions that would have killed me if I'd lived a century earlier, I can remember events -- as an adult -- that happened 30 years ago, and I don't have the physical stamina, mental agility, or energy of a 30 year old any more. (Mind you, what they say about experience trumping youth and enthusiasm? It's not exactly true, but the experience factor makes up for a lot of the gradual cognitive decline that comes with age.)<p>Like Jacques, I'm less inclined to put up with fools -- but I'm also less inclined to get worked up over things. And I'm probably unemployable these days. (15 consecutive years of self-employment will do that to anyone.)<p>But the biggest thing I've noticed? What look like big opportunities, vanishing in the rear-view mirror of age. When you're 30 you can think in terms of going back to university or forming a new start-up. You've got time to plan a new career or nurture a business ahead of you. But by the time you've hit 50, the future is looking cloudy. You don't want to train for a new career to see you through the next 30 years because who the hell wants to be working to pay off student loans when they're 80? So you get locked into whatever track you set yourself running down twenty years earlier. Changing is hard because you have less of a future ahead of you to change <i>for</i>.<p>If you're under 35, my advice would be to think about that. Do you really want to be locked into doing more or less what you're doing now when you're in your sixties? If not, now is the time to change. The later you leave it, the harder it will be.