did-you-kno:

In 1946, a South African child who
dreamed of being a scientist wrote to
Albert Einstein, and they became pen
pals. A few letters later, she said she
regretted being a girl, apologized for
not telling him sooner, and hoped he
wouldn’t think less of her. He quickly
replied, ‘I do not mind that you are a girl,
but the main thing is that you yourself
do not mind. There is no reason for it.’ Source Source 2 Source 3