Einstein's way of thinking

He ran little experiments.

At age 16 he wondered about riding alongside a ray of light. What does light look light for a moving observer? Light would always look like it was moving at the same speed. Other's were thinking about this also, but his thoughts were more visual.

When thinking about theory of gravity, he imagined riding a falling elevator.

He was also extremely stubborn. He didn't trust experiments not confirming his ideas. Trusting his instincts was mostly correct.