Well, I heard an anecdote about Einstein many years ago - he was writing one of his articles about GR and wanted to make it understandable to the general public, so he read it to his granddaughter (or something like that), who was only about 5 years old, thinking, if she can understand it, then of course everybody else would as well. And, amazingly, this young child, who was playing happily with her stuff while listening to her nice graddad, would yes "Yes" every time he asked if she understood what had read out. I think it is a very sweet story
Another saying that I have seen attributed to Einsteing is, that you should always strive to make things as simple as possible, but no simpler. GR is a good example of this - it is a remarkably simple and elegant theory, and you really couldn't make it simpler; but it is still bloody complicated, not least because the toolset required (differential geometry on a smooth manifold with a Lorentzian metric as well as a volume form) is rather complicated in itself. C++, I suppose, compared to C, is like GR compared to Newtonian Mechanics; it gets really, really crinkly around the edges, not because the idea is unsound, but the subject just is that complicated, when you pursue it - and you can't make it simpler without losing important bits.