Have you ever read a book that started out something like this? I nearly scream every time I see it.
I was an average teenager. So average, in fact, that when you look up average in the dictionary there's a picture of me. I lived in a normal house with a normal family and a normal dog. I wasn't ugly, but I wasn't pretty. I was okay at everything but not super-awesome at anything. I was just...normal. Nothing special about me.
You especially see this in paranormal/supernatural romance books. *shudders* This is an exaggeration, but you get my point. The problem with all that is this: nobody is normal. Nobody is that average. We've all got something, whether it's big or small, to set us apart. Everybody is unique. Maybe you've got a secret passion for water ballet, or you're a master rubber-band shooter, or you've watched Harry Potter thousands of times *waves to BBF*, or you're desperately wishing for a time machine so you can live in medieval times.
Are you with me? Here's the point: If nobody is really like that in real life, then why would our characters be like that? And anyway, who wants to read about that? There's no reason for readers to like that kind of character.
Think of it this way. Who doesn't love Ron Weasley? He may seem normal at first glance. But then you look deeper, and you can see that he's fiercely loyal, has a zillion brothers, loves Hermione Granger, and is afraid of spiders. Those are all things that make him unique, and it's for those reasons that he's such a likable character.
So next time you're developing a character, don't go for the supreme-averageness cliche, because it's simply not real. Not to mention overused. Call me up if you can actually find a human being like that. It just doesn't happen. Instead, find some way to make your character special and unique. Your readers will thank you for it.
PS What's the kitten for? Well, it's peeking out of the washing machine mentioned in the post title. Why a kitten? Because it's cute. Why not?
PPS Oh, yeah, the tag? Yep, that's a Despicable Me reference. Glad you caught that.