Maybe, you fucking buffoon, the reason I didn't give my phone number is because I don't want you calling me, pestering me for your business, when the only reason I filled out the form was to get a vague idea of how much something costs, in this case putting something in storage for a few weeks.
If you've not done it before, how the fuck do you know how much it costs to put something in storage? I fill out the form to find out, and, this is the clever bit, I'm asked to include my phone number so they can tell me my quote over the phone.
The problem is that I'm a normal man, and I therefore don't much like talking on the phone. If you do like talking on the phone, you're either female, a sadist or a cunt. The gigantic industry of bastards who try to sell things to us every minute of our lives (where you are, right now, can you see an advert for something? of course you can) have cottoned onto this, and realise that people who find phone calls unpleasant will do anything to make them end as quickly as possible. Some people will tell an unwanted caller to fuck off, whereas others might do something as insane as agreeing to buy whatever is being flogged to them, just to be able to end the call and get their life back.
If only there was a way to prevent this unwanted invasion of your mental space by these loathsome, capitalism-driven arseholes. If only it was possible to, for example, always put a telephone number other than your own into that box.
I suppose the fact that I put my phone number as 020 819 80085 didn't give it away?