You can't have your cake and eat it too

I never quite understood the whole saying " you can't have your cake, and eat it too" to me that saying never made much sense, tell me what"s the whole point of getting a cake and not eating it and although it's a figure of speech i still don't think it applies.  I recently read a blog where the chick used the quote comparing it to her life where she feels contained.  In my personal opinion no matter how much someone tries to put limits on our lives and take control they never can unless we allow them, we are the chaufor of our own lives and we control the path we choose to take and no one else.  Life in it's own is a challenge and it's up to us to figure how to deal with it, i strongly believe that god would never give us something we can not handle.  And usually defeat is a figure of our own imagination.  We make the decisions to do and say what we please how else do yo think we learn and grow.  It's better to have made a mistake and grow rather than to regret and wonder why.  Thats how we grow into the person that we are.  So life is what you make of it and what you allow it to become.