Actually, now that I've seen the film, I feel that I'm a lot like Mario.
You see, I actually have a brother, and we're also twins. Me and Mario, we're both the older, shorter (canonically, we're the same height), and probably chubbier of the two, and we're somewhat picky eaters that never liked mushrooms until we did.
Unfortunately, we're both undervalued by those around us, teased for our small stature, and feel like we're failures that've given the whole world up. Despite this, we're friendly, helpful, and fiercely loyal to those we care about, and we're not quitters, no matter how tempting it is to throw in the towel and call it a day.