The rain the night before the battle made it harder for napoleon to get his cannons into position. When they did commence firing, the effect on the British line was mitigated by the cannonballs sinking into the mud instead of bouncing along as usual.
And around the late afternoon, Blucher arrived in the nick of time with Hanovarian reinforcements. Granted that the Iron Duke made good use of the reverse slopes and was a master tactician, but he also had a good run of luck that day. What if...?
What if history had been very different? Not just at Waterloo, but at other times and places? What if Napoleon had managed to conquer Europe?
Now, this may seem almost heretical to some, but would the ordinary people of England have been worse off as a result? Might they have even been better off without the dubious 'benefits' of the British Empire?
Oh, the British aristocracy did very well out of the way events turned out. I am not so concerned about them. What about the workers? Had Napoleon made the French system of law the standard across Europe, would we be any the worse for it? If there had been a European union in Napoleon's day, might we have avoided two world wars?
What exactly did the British working class gain as a result of all those military victories over the French? Well, we got cheap tea and sugar, and pretty flags to wave - but the lions share of the money went into the pockets of the rich upper classes. Might not ordinary people like myself been better off with Napoleon in charge, I wonder?