People say this as if it's some reminder of a Horatio-Algiers-like rise to greatness, but like if Einstein hadn't worked at the Patent Office, he wouldn't have seen the countless patents that show diagram upon diagram, painstakingly explaining the proposed mechanism(s) and advancements in terms of gadgets and thingamabobs, that very may have well fueled thoughts which led to his declaration that mass and energy were interdependently related, with one being the equivalent of the other as either end of an equation. Originally, it included the velocity and momentum of a particle in question, IIRC, but if you zeroed-out those variables (which is sort of a Laplacian conjecture, if you ask me), you arrive at the simplified E=mc^2.

I've read enough of what Einstein wrote to know that if he were alive today, the last thing he'd want to be called is a genius, and that he never promised to know more than he did.

What people fail to appreciate about his famous quote that "God doesn't play dice with the universe" is that it simultaneously asks you to imagine both God and the Universe, and describe the difference.

He's subtle like that.

Because if you don't imagine that there's any difference between them at all, then there's no way they could play dice in the first place, since that requires two separate opponents rolling a cube of bone across a flat surface.

So there's no problem with quantum uncertainty. It's just a thing we're continuing to discover the limits of, just like Einstein was reconciling with the speed of light.