How can a man go eight days without sleep?

The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

John went to a parrot shop in Mexico, and the parrot owner told him that his parrot is so unique that he repeats everything he hears. John got excited and immediately bought the parrot. John went home and spoke many words, but the parrot does not repeat anything.
He went again to the parrot shop and complaint to the shopkeeper, but the shopkeeper never lied. Explain?

Can you make a fire with just a single stick?

How can you leave a room with two legs and return with six legs?

Find the missing number in the series below

13 -21 34 -55 ? -144

What is full of holes but still holds water?

Can you place three balls such that the equation shown in the picture holds true?

What do you see in the given picture?

Can you write down eight eights so that they add up to one thousand?