The earliest match for this popular quotation appeared in an essay by Theodor Reik in 1965. Currently, he is the leading candidate for coiner of the saying.
Ah, interesting. I just did a cursory Google search for the author of the quote and it said Mark Twain. Guess someone should file a bug for their knowledge graph team.
A cursory search might even give one the impression that Einstein had an opinion about bees. (Unkillable memes are pretty interesting.)