I have a message for members of Generations Z and Alpha. In the aftermath of the events in Tennessee, you have received well-deserved praise for standing up for the causes you believe in. From Parkland to Nashville; from climate change, gun violence prevention, to the defense of democracy—you have shown your courage, energy, and principle. But as a member of the most hated generation right now, I must give you a warning.

Sixty years ago, people of my generation were the ones protesting. We were the ones marching for civil rights, women’s rights, and LGBTQ+ rights. We were the ones protesting the Vietnam War. We led boycotts, sit-ins, and walkouts. We condemned our elders for their indifference, greed, and reckless endangerment of our planet. We were attacked by racist mobs and police. Four of us were shot and killed at Kent State. But we persisted with the belief that our generation could save the world. We did achieve progress in expanding civil rights, ending a war, lowering the voting age, and achieving freedoms that, until recently, you’ve been able to enjoy.

But we made two fatal mistakes.

First, we thought we were done. When we passed the laws and got the Supreme Court rulings we wanted, we thought those rights would be secure forever. “Roe v Wade is settled law”? That aged like unrefrigerated milk. We didn’t pay attention when far-right think tanks and Christian fundamentalists started packing the courts, taking over local and state governments, redrawing congressional districts, and controlling school boards. All the things we thought were dead, like Jim Crow and virulent anti-Semitism, have burst from the grave. Now, all the progress we made since FDR seems to be unraveling.

Second, we sold out. As we got older, we started building careers and families. We bought homes and cars. We had mortgages, loans, and savings accounts. Now, we had things to lose. So, we traded our idealism for what we thought was pragmatism, but it was really fear, cynicism, and greed. We stopped doing what was right and focused on what was safe and profitable. Even if we were to lose the progress we fought so hard to gain, as long as it didn’t affect us, we stayed out of it.

We became the elders we raged against when we were young.

The powers that be hope you’ll make the same mistakes. When they realize they can’t subjugate you by force (like they did to us in the 1950s and 1960s), they’ll give you a little bit of what you want to quiet you down. Maybe they’ll roll back some of their draconian laws. Maybe they’ll agree to some reforms. Maybe they’ll put some flags and rainbows on their products to make you feel included. You will appreciate the progress. You may feel you’ve finally won. And they will plot to snatch that progress away from you again.

It may be harder for you to sell out the way we did, given all the ways they’ve rigged the system and trashed the economy. You’re not able to move up in your careers because we can’t afford to retire, and the only way many of you will get a house is when you inherit it from us. But you will eventually have careers and families that will make it harder for you to speak out against injustices—especially the ones that happen right in front of you.

That’s why I urge you: Don’t make the same mistakes we did.

Don’t let progress make you comfortable. We will always have racists, autocrats, and wealthy sociopaths. Never let down your guard.

Don’t give up your idealism. Hope enables us to survive as a species, even in our darkest and most dangerous times. A just and humane world is worth fighting for.

Don’t let success make you fearful and selfish. When we help others succeed, we succeed as well. Ayn Rand is wrong.

Don’t fall into despair, no matter how hard things are right now. Here’s where we can help, because we’ve been in those battles before. We faced setbacks and heartbreaks. Learn from us about how to regroup and persist, and know that real progress is possible.

And for people of my generation, we need to tap into the idealism, energy, and determination we had when we were young. We shouldn’t just sit back and praise Generations Z and Alpha as heroes. We should be joining them in the defense of freedom and justice.