Hi,
Several comments:
1.  Keira Knightley is not at her best. 
2.  She is not really topless (I mean she didn't expose
     too much).
3.  I don't think she shows a girl's body.
4.  My impression is that Keira Knightley is much more 
     smart than beautiful.   
5.  And the main point: Why do you have to compare
     yourself to her ?.... You sure have values and qualities
     she doesn't have (and she has values and qualities
     that you don't have).  If I see a nice guy "well built"
     I don't even bother to compare my body to his.....
6.  Better love what you have and what person you are
     and appreciate it !.
Best rgards,