Probably my favorite anecdote about the grid synchronization behavior is that the generator governor settings (e.g. how to react to changes in frequency) were developed early in the 100 year+ history of the grid, and now we don’t fully understand why the settings were chosen to be what they are, and all the engineers who developed them are long dead.

Now that a bunch of wind and solar is being added to the grid with completely different control schemes, there’s a lot of concern about whether the system will continue to stay reliably synced.