I once interviewed a guy who told me a too-long sob story about losing all his PhD data and thusly leaving university after three years with pretty much just the lousy t-shirt to show for it. I may have been less than charitable, if you've three years of priceless data that your entire qualification depends upon, I'd expect a doctoral candidate to have the nous to back that shit up. (Not discounting the likely fact it was BS to cover that fact he'd failed to obtain his PhD, in which case learn to bullshit better.)
Certainly in the Apple-verse, Time Machine makes back-ups simple. Plug in disk and erm, that's that. Of course, it's sensible to keep important stuff online or at an alternate location too, on account some miscreant runs off with the backup disk or other calamity. Mine goes to the box under the stairs and up to the clouds.