User-defined function to reset variables?

[Mark17]

This is why classes were invented: to group in a single entity variables shared by different places. So create a class (or several classes) to hold the variables

I've studied some intro stuff about classes, but they really confuse me (along with all the syntax like the __init__, the self, etc.). Can you explain this in a simpler way? If I clearly understand their place and am convinced it's worth doing, then I'll force myself through it and figure it out.