It was even worse for some games that didn't check to verify that you had the correct version installed and patched before it started its patching process. Then you get done and get an error that X file is missing or an incorrect verison. And you couldn't just get that version from someone else's install because then you'd get an error that Y files is missing or an incorrect version. Rinse and repeat. It was easier just to completely start over and make sure you got all the patches installed in the correct order.
It got to the point where I'd make a backup of the install every time I was finished patching so that if I came back to the game later and there were 5 patches waiting to be installed, at most I'd only have to redo those 5 patches if I forgot one rather than all the patches since the game had released.
Not all games were that bad, but when you ran into one, man was it aggravating.
Steam just made PC gaming so much nicer in that respect. Even if you'd missed 10 patches since the last time you played, you just update the game and it's good to go.
Regards,
SB