Sometimes, just for experimentation, to see if I could have accomplished something differently.
Once, when the AI built a wonder 1 turn before me, I reloaded about 10 turns back, and flocked workers to my city building the wonder to mine every possible square to boost production.
I ended up knocking 2 or 3 turns off of the total time needed to build the wonder. . . and you know what?
the AI still built the wonder 1 turn before me . . . . .<sigh>