Years, since I've seen Knightrider, but Michael totally
had angst! I think Michael was actually dead (not in zombie way!). Michael Surname-I-Can't-Remember was this ordinary guy, and then one day there was an accident? (attempted) murder? something involving fire? involving Michael and everyone thinks he died, but he's actually rescued by ythe Knight Foundation. Michael wakes up hours? days? months? years? later and discovers that his previous life has gone and he's now Michael Knight. (And I think there was some sort of plastic surgery - he doesn't look like his old self - which is why I think there was fire (and a badly burned Michael) involved.)
I can't remember how Devon (the Guy In Charge Of Knight Foundation) got Michael to start Fighting Crime; whether Michael agreed because he didn't have anything better to do, or if there was A Vendetta (see above re: murder?).
Also. I think Michael had a Love Of His Life when he 'died' which was also cause of some angst.
And all of this is what I remember of the proper Knightrider. I know nothing of the new one.