I'm going to read that article linked by blackMamba. But I have to say, this sort of thing really annoys me.
I changed my surname while in my late teens. I had absolutely no problems at all. Then, in my late 20s, when I started nurse training, we were all presented with a form from someone asking a load of impertanent questions.
Now just a bit of background. In the NHS, these forms do the rounds all the time, either asking about patients or staff. Their purpose is to justify the existance of some newly appointed idiot to the senior staff, who won't ever have a proper job to do, but will have almost secure employment for life. It's one of the more obvious corrupt practices in the NHS and given their failure to deal with it, demonstrates that they will never deal with any of the other examples.
Anyway, this form, like all of these, asked a load of silly questions, I think these were asking about when we first decided to become nurses and why. The form wanted to know if we had had a previous name, though this was mainly to see which females had married.
Now I can't quite recall why, but for some reason, the issue of name changing for nonmarital reasons came up and it was said we had to answer regardless of the reason. So I did.
I was put through the third degree by any number of staff. Each claimed it was unusual for a man to want to change his name. They wanted to see if I was hiding anything, (as if I would have told them about the name change if I had been!!). Most demanded to know what legal procedures I'd used, though it became fairly obvious that none knew what these were. Most seemed to think it was like some sort of American court as seen in a 50s B movie!
It was sorted out in the end. But a heck of a hassle.
If you think you can, I will suggest you simply ignore the question or even deny it.