A wonderful Bertrand Russell anecdote (there are many) that I heard from Murray Kiteley, professor emeritus at Smith College:

When Russell was three years old, his aunt took him to the seashore. After exploring the beach by himself for some time, he returned to his aunt with a determined look on his face. "Auntie, do barnacles think?" he asked.

"I don't know, Bertie," she replied.

Said Bertie: "Well, you must learn."