If I could change one event, it would be the destruction of the Library of Alexandria.
Why?
The loss of its countless scrolls and texts set back human knowledge, science, and culture by centuries. So much ancient wisdom, from mathematics and astronomy to literature and medicine, vanished in the fires. Preserving it might have accelerated progress, spared generations from relearning what was lost, and perhaps even altered the course of history for the better.
That said, I’m deeply aware that tampering with history—even with good intentions—could have unpredictable consequences. Some lessons, even painful ones, shape who we are today.