What did you learn this month that surprised you?

[WormholeX]

We all pick up random bits of knowledge as we go through life. Some come from documentaries, some from books, some from conversations and plenty from falling down internet rabbit holes late at night. Occasionally something surprises us, changing how we see the world or simply making us say no way out loud

This month, I learned that octopuses have three hearts and blue blood. I also discovered that the Eiffel Tower can grow taller in summer, because the metal expands in the heat. Neither fact is useful in daily life, but both made me stop and think for a moment. That is the joy of learning random things

It does not need to be a fun fact, though. Maybe you learned a new skill, discovered something about your family history or realised something about yourself. Perhaps a news story or a forum thread here taught you something you did not know. Practical tips count too, like a better way to cook rice or fix a dripping tap

Please mention where you learned it if you can, so others can look into it further. A bit of healthy scepticism is good too, since plenty of popular facts turn out to be myths

What did you learn this month that surprised you?