I'm reading The Anatomy of Fascism by Robert O. Paxton and learned that, earlier in his life, Mussolini was a schoolteacher. My first thought was, Imagine being a former student of his as he ascends to dictatorship. That struck me as a bizarre experience to have. My second thought was, I wonder if there are accounts from folks who knew them before their respective rises, and if they had anything to say about their personalities and ways of life during that time.
I think the best most recent account of Hitler's life prior to his rise in politics is contained in Ian Kershaw's Hitler: A Biography. I can't recommend this book highly enough. It is both authoritative and entertaining. I read this several years ago, so my memory is spotty, but Hitler as a private citizen was recollected as fairly unremarkable.
For instance there at times has been a myth that Hitler was extremely poor after WW I and before his rise to power, but Kershaw states that while Hitler did live in a men's home from time to time after the war, he was also sent fairly regular sums of money from his doting mother, who he often pestered for more cash. He hailed from a slightly upper middle class family background. He didn't come from da streets. :)
He was generally well regarded as a soldier during WW I. Somewhat withdrawn and serious, but not unpopular with his comrades. He won several medals including the Iron Cross First Class, and served as a message runner during WW I, which could be a very dangerous job. By most accounts he was a good soldier and comrade, and his service in WW I was one of the happiest times of his life.
He was kind of a lay about and not a great student, but not really in an unusual way. He was just somewhat intellectually lazy. Much preferred bumming tickets to go to the opera over buckling down over his studies. This is a big reason for his failure as both an artist and a prospective architectural student. While he wasn't completely w/out talent, (his postcards aren't bad), he lacked the natural talent in art or architecture that might have made up for his generally lackadaisical work ethic. A style that he displayed as dictator of Germany. He kept a rather bohemian schedule in which he slept in late, screwed around most of the day, got to work in the afternoon and worked into the late evening, then repeated. Often described as a procrastinator.
He was an excellent politician. He was good at organizing and originally saw himself as a behind the scenes guy. He early on described himself as the "drummer boy," playing the tune but allowing others to lead. But he turned out to be a brilliant speaker, and was far too headstrong to not want power. His performance during and after the Munich trial I would again say was brilliant. Both for burnishing his national image in a forum where he was on trial for treason, and for showing that the National Socialist movement was hopeless w/out him while he was in (a very comfortable) prison.
He is described socially as somewhat awkward, but again not incredibly so. Thought of as a bit of a rube by the upper class once he started running in those circles, which of course he was. He was considered comically awkward and uncomfortable around women. Chivalrous and extremely polite, but in an antiquated kind of way. Very much a "m'lady" kind of guy. Described laughingly by Helena Hanfstaengl (wife of early Hitler upper class ally, Ernst) as almost sexless.
tl;dr - He was a somewhat lazy and socially awkward guy, but not one without friends. He loved Wagner, was a good soldier, was a bit of a boor in social situations who tended to drone on and on, not smooth with the ladies, but was a damn good politician.
Edit: Some corrections from other posters. Hitler's mother died in 1907, so he wouldn't have been pestering her for money after WW I. I do recall Kershaw mentioning this of Hitler when he was younger.
Here is some of what /u/commiespaceinvader has written/said about Hitler as an agent of history:
See also What was Hitler's stake in the Holocaust? answered by a now-anonymous redditor
From /u/Georgy_K_Zhukov:
u/Klesk_vs_Xaero answered a related question last year:
Benito Mussolini worked as an elementary school teacher for a while. Was he a good one?