Physically can't because the program/code behind the site (or whatever) doesn't allow you to, or just because you made the rules like that?

I know I'm squeezing the proverbial lemon here and probably being more than a little annoying, but it just seems silly that just about nothing can be changed, and we don't have the ability to do so ourselves. 

At any rate, if it [i]is[/i] because it's just not possible, then I would've liked to be told that from the very beginning. I apologise for being annoying, though. Whichever the case may be.