Remember learning your scales for music lessons? Rough stuff, right? The same thing over and over. Did you ever get to that point where you noticed that learning your scales (and repeating them over and over) made it easier to play things by ear? If you didn’t, go out and buy yourself a cheap keyboard, practice your scales and then see if you can play all the nursery rhymes you know without having to look up the sheet music on the web. In other words, see if you’ve improved your ear.
If you did get to that point where you realize that learning scales improved your ability to hear the “bigger picture” then you might be able to appreciate the notion behind kick combinations. You practice these sequences over and over until you don’t have to think about them. It’s a lot of work. But after a time, you realize that you can see more kicking opportunities in sparring and maybe part of that proficiency is all that time you put into practicing your combinations. (No doubt all the sparring practice had something to do with it as well.)
So, if you find yourself unable to make it into the school this December because of ice, holidays or whatever else might happen – make martial use of your living room and drill your kick combinations for 5 minutes.