"Have no fear of perfection you will never reach it- Salvador Dali" 

I think we have all done this more than once. 

well..i have done it to -

hide my vulnerability, 

my weakness , 

or

because i don't expect  people to understand me.

But i guess that's okay because i truly believe that there is nothing wrong in crying but wiping those tears yourself and holding your strength togather....that's where lies the real credibility.