Throughout his youth, William James (1842–1910) seemed seriously mixed up. He began college as a chemistry major, then switched to anatomy, then set sail on a biological expedition to the Amazon, and then traveled to Europe, where he became interested in the new science of psychology. Luckily for us, he stuck with it for a while.

LETTERS TO WILLIAM JAMES FROM VARIOUS CORRESPONDENTS AND PHOTOGRAPH ALBUM, 1865–1929. MS AM 1092 (1185) #8, HOUGHTON LIBRARY, HARVARD UNIVERSITY