According to quantum mechanics, existence of an electron at a place depends on the wavefunction which in turn gives us the probability of an electron being there. And for a few special places, like nodes in an atom, the probability of finding an electron diminishes to zero. But at every other possible point in the whole universe, there is some non-zero probability of finding an electron. This is what I know (correct me if I'm wrong).
Now this is my question. Let's suppose an electron wandered far away such that now it is more closer to the nucleus of another atom than it is to it's original atom's nucleus. Now how does the electron know that which atom did it originally belong to? And with so many number of electrons surrounding us, this process of intermixing of electrons from one atom to another should happen quite spontaneously. But as far as I know, we don't see electrons moving from one atom to another quite often. Yes, there are cases of ionic bond formation and conduction where there is apparent movement and transfer of electrons, but why not everywhere?
And the implications of electrons "getting lost" are drastic. Electronic configurations of atoms would no longer matter. Almost all the matter around us would get ionized, and also emit (hopefully) beautiful and colourful line spectra. But in reality, non of these fantasies exist. Why?