OPs nick Yidna is Andy pronounced backwards.

In my family we used to do that, call each other by our backwards name. Later in life I read that this was a Scottish thing, to call your children backwards for the superstitious reason that the bad spirits wouldn't recognized them, or something like that.

For instance a girl could be named Senga in Scotland, which is Agnes spelled backwards.

I think it's funny because in my family with Scottish roots we would do it for a joke, not knowing the origin of it, or that there even was an origin.