Einstein's first great thought experiment came
when he was about 16. He had run away from
his school in Germany, which he hated because
it emphasized rote learning rather than visual
imagination, and enrolled in a Swiss village
school based on the educational philosophy of
Johann Heinrich Pestalozzi, who believed in
encouraging students to visualize concepts.
While there, Einstein tried to picture what it
would be like to travel so fast that you caught
up with a light beam. If he rode alongside it, he
later wrote, "I should observe such a beam..."
http://mobile.nytimes.com/2015/11/01/opinion/sunday/the-light-beam-rider.html
