Kids ask 300 questions a day.

A 2013 U.K. study from online retailer Littlewoods.com observed young children and recorded the questions they asked the adults around them. The children tended to turn to their mothers for answers, and these moms could end up answering an average of nearly 300 questions per day, or one question every two-and-a-half minutes, the study found. The moms reported that the hardest questions they were asked included "Why is water wet?" and "What are shadows made of?"