As I got older and I reflected on all the grumpy old men waving at the clouds and complaining constantly about this-or-that being better in their days when I was a kid, I realized why.

Now I'm the old man and I avoid becoming bitter my reminding myself of the following truth:

• When you're a kid, the world belongs to the grown-ups - your parents, adults of authority around you.

• When you reach teenage years, the world starts being yours: you've developed tastes for things people your age do and create. As you go through puberty, your identity is reinforced with things of your time, and other young people your age with which you do the same things. You all have a bright future in front of you.

• When you get out of puberty, hopefully you get our of school and start working: the world is fully yours. The trendy things in the world are things you find trendy too. Other people speak like you. You're not a powerless kid and you're not weaker old guy/gall yet. You're fully part of it and it suits you. You may not like the world, but it's yours. It shares your values and your values are what makes the world go round at that point in time . Your personality, your cultural identity and the cultural norms you respect, and your value system are fully developed, and a pure product of their time.

• And then they stay that way. But the world keeps evolving. Slowly but surely, the things you learned become deprecated. The things you like become old. The way you speak becomes strange to younger ears. The values you believe in no longer apply. The world slowly shifts beneath your feet, but it's happening very slowly, year after year, until...

• You reach an age at which you're very visibly and obviously out of sync with the world. Even you notice it at this point.

And here lies the trap: you can either reflect on how the world has changed and acknowledge that it's not your world anymore, but it's younger people's now. People who are now the age you once were: it's their turn to have a go at owning the world. You're just in it for the ride.

Or you can take refuge in your old values, wallow in the old things you've liked for decades, and bitch and moan about the world going to shit. It's not going to shit, but it feels that way to you. It's easier to reject the world around you than admit it's just not how you like it anymore, but it's poisonous: it turns you into a bitter person everybody hates.

I choose to ignore the things I dislike - which, at this point, constitute a lot more of the world than the things I like from the past, from my youth. But I also choose to not pass judgment on them because they're not from my world: they're from today's youth's world, and I have no say in it.

If you're old and angry, think about this. You might find some comfort in letting go.

The corollary of all this is: there is no better America in the past: the past simply seems rosier to older eyes. America has always been as great or as shit as you find it to be today.