Work Vent

So just a quick little work vent.
Do you keep any personal things at work that you use on a daily basis?
I do.. like lip balm (for the incredibly dry office due to the heat on full blast), hand cream, lens cleaner and eyeglass cloth wipe (I hate smudgy glasses).
You get the idea.
I'm not one of those crazed people that has a "stapler" that is mine etc.
And in terms of office products I'm not really all that concerned.
But there is someone at my work that like to borrow my lens cleaner...EVERY single day.
And she asks "do you mind if I borrow some it just works so much better than just water"
No sh*t thats why I went to the store and spent the $9 on it. 
And she asks EVERY SINGLE day.
And then she apologizes after (maybe its the Canadian thing?!).
But my non confrontational self would never respond with a "hey go buy your own" or leave it at home one day. 
I just find it so irrritating and why do you apologize and ask ...please buy your own lens cleaner. 
Am I being ridiculous?
How often is it okay to "borrow" someones item?
I swear it's not that I don't like to share but I just feel annoyed.
Teagan