Throughout his youth, William James (1842–1910) seemed seriously mixed up. He began college as a chemistry major, then switched to anatomy, 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