We all have asked ourselves this question at some point in our life. A colleague of mine (and by colleague I mean a member of the UK economics community, not the same uni as me) took the next step: wrote a paper about it.
Here is the link: [url]http://www2.warwick.ac.uk/fac/soc/economics/staff/phd_students/backus/girlfriend/why_i_dont_have_a_girlfriend.pdf[/url]
Have fun - bearing in mind that this is just a "fun" paper: it was written just for the sake of having a laugh, and was not written with having in mind academic rigour - or even accuracy. Contains many mathematical inaccuracies, but it may make you feel better (or worse!).