yes, pretty much every b-school admit is an over-achiever.
i'm kidding but there's some truth to that. at Wharton, you don't have anyone who is relatively normal in terms of their career progression. at the very least, they excelled at something...whether it's school or career or in many cases, both.
for the most part, a guy who went to a regular top 50 type school and got Bs and Cs and worked at a no-name company for 2 years as an entry level employee and never got much more than the basic salary + minimal raises and scored a 600 on the GMAT and wrote mediocre essays saying "i sort of what to go to b-school because it's something to do"....doesn't get into a top b-school.
My Wharton Blog - http://www.whartonblog.com
Wharton MBA for Executives Ambassador - http://gmatclub.com/forum/128-t66295
My Story - http://gmatclub.com/forum/102-t49770