I love this so much. I've always held the belief that she was smarter than she lets on. Maybe a bit clumsy, but that's not all that surprising. Physical abilities and mental abilities are two totally different things. A person(or pony) can be pretty smart, but lack physical prowess/ability. And vice-versa. All the more reason to never judge someone(-pony) by their appearance.
I always thought Derpy was a lot smarter, too. She's just clumsy and accident-prone, that's all. Kinda like me.
I was born with deformities in my knees; they point inward instead of straight out, making my legs not very bendable or flexible. I have also struggled with poor physical coordination since childhood. Derpy and Clumsy Smurf are my siblings in that department. So imagine the big smile on my face when I saw teenage Derpy as an honor student, which I also was back in high school. My favorite pony breaks the stereotype! And I suspect the glasses are to correct her wall-eyed vision.
Now we know Derpy's diagnosis: Asperger syndrome or other light form of autism. I have 2 friends with that diagnosis: both looks a bit clumsy and funny, but one are very good writer and translator, another one history student, who knows almost all historical events like walking encyclopedia. Or otherside: Derpy are pegasus and she have many chances to get death or badly injured. Maybe small brain damage, what does her clumsy, but not stupid.
A bit know (maybe i forgot, what form that guy haves): that guy who learn history, was in school age badly retarded and pullied by other schoolars. He ended college almost 10 years later than others. And is 10 years older than other history students on his group.