As I scrolled through my Twitter feed two days ago, looking at all the images of sunsets and selfies in front of international monuments of the travelers I follow, I saw an image that seemed like the fever dream of the Pope. Notre Dame, the iconic gothic cathedral in the literal heart of Paris, was engulfed in a plume of smoke.

At first, I thought it was an illustration. A reimagining of the fire that I may have not read about while reading the history of the Cathedral during my visit in 2017. But I soon realized instead that I was witnessing history reel out in real time. It was clear to me that probably for the second or third time in my life, I would have a “do you remember where you were when…” moment to share with my grandchildren.

And then I thought of something else. Something that most people who are not travelers probably never would. I thought of all the people for whom visiting Notre Dame was a dream. Of those who had the image of her edifice taped on their vision boards and inside the pages of notebook where they kept their bucket lists. I thought of all the people who were certain that someday they’d get to see it. That someday, they’d be able to make the journey for themselves.

And what haunted me was the assurance in their minds, in all our minds, that’d it would still be there whether they were ready or not. The confidence that this icon would remain central and centered in the most beautiful city in the world long after this civilization was gone. And like Stone Henge and the Pyramids before her, those who came after us would spent countless hours admiring her beauty and debating about what those who built her was on about.

But as one of my favorite singers once sang, “Forever doesn’t last too long.” For all our faults as triumphs as humans, it is important for us to remember that nothing in this life, on this planet will sustain in perpetuity. It is doubtful that anyone who has ever even heard the name France would also not know about her most famous place of worship. And at moments like this, we must remember to be respectful of the only thing in life that is certain—the passage of time.

So, for all of those with your bucket lists and vision boards, I encourage you to live responsibly, be also remain aware that time isn’t on your side. So do what you can while you can to enjoy this life because forever doesn’t last forever. And you don’t want to wake up tomorrow and realize that what you are waiting your whole life to do or experience is no longer there.

So, start living today.