Try this to find out!
Read the rules here first because they're in Japanese.
1. Click on "Start."
2. Wait for 3, 2, 1.
3. Memorize the positions of the numbers on the screen, and then click on the blank circles in order from the smallest to the biggest number.
4. You'll do this ten times, and then it'll calculate the age of your brain.
I've played twice, and I'm happy to report that my brain is 6 years younger than I am.
Try it yourself and see how old your brain is.