As students approach the college admissions process, I find the unicorn question to be a helpful one.
The question could be rephrased as "What do you excel in?" But, I'd rather rephrase it as "What do you value? Are your values apparent in your life?"
I prefer the second translation because in order to reach a level of excellence in an endeavor or realm of life, one must maintain some consistent core values.
Ethan Sawyer's "Values Exercise" is a helpful one for teens (and perhaps adults also). Here is a link to that exercise.
And then, what do your friends and family admire about you? The answer to this question likely ties back into your values -- but it is another way of assessing some of your core values.
Food for thought. I'll be thinking of my unicorn qualities also!