Like with the optical illusion below, for example, that I brought to test you today. I recently shared it with four of my colleagues, but only one got it correctly right away. In other words, it’s difficult. I had to...

How many circles can you see in the picture? We all love riddles and train our brains, and it's a good choice. Are you ready to wake up and face this puzzle? Here comes the challenge. It’s not proper math, but...