How to define “unconventional”?

Some people may think I am an “unconventional” person. Yes, sometimes I have to agree. But how to explain yourself as someone “unconventional” in a job interview? The question really irritated me and I didn’t know a good answer. Defining yourself as “strange” or “irregular” would not have been a good match for the job, neither is “crazy”! May be “unusual” or “original”?
I could not explain the core of my character! I felt as if there are no words for it. And being out of words is not a good reference for someone working in communications! Well, in the end a task in strategic thinking helped me out. How is the angle between the hands of a watch if the time is 3:15? I don’t know why PR people need angles but the answer is 7,5°. My solution method was so unconventional that even my interview partners had to agree!