The story is so well known it has practically become a cliché:
When Einstein revolutionized physics in 1905, he was working at
a patent office. He was 26 years old. This wasn't some short-
term, temporary gig: he had been there since 1902, working on
his new ideas during his spare time, mostly without the benefit
of close contact with the established scientific community. The
impact of his work was not immediate; he would remain at the
patent office for another 4 years, until he turned 30. He didn't
gain a permanent post until 2 years after that. Still, he was
only 32 years old then, practically a child by today's
scientific standards. So what was one so obviously gifted--who
was destined to revolutionize not one but three fields of
physics that year--doing working at the patent office? That
question could be answered many ways, but here's one: His job as
a schoolteacher didn't work out. Here's another: He was working
at the patent office because he failed his engineering school
entrance exam in 1895. Einstein