A girls struggle in a mans world

Source: http://www.jillposener.com/photodetail.cfm?file=FiatAd.jpg&category=graffiti

How come that, in the year 2011, after having worked in the same field for over 10 years, having proved myself over and over again, I still have to hear comments such as "I suppose science wasn't your favourite subject in school?" or "Well that shouldn't be a problem for you because you are cute ;)" or, the most frequent one, "You must be the assistant?". 
Now why would you assume that??

 Just a thought on a Thursday morning.... Raaaaaawwwwwrrrrrrrr!

xox