Easily built, easily broken?

Do you believe that with 'love and relationships' what's easily built will be as easily broken?

Is she afraid that you'll fall out of love just as fast and just as hard as when you fell in love?

OR maybe...
She's afraid that you'll fall in love just as fast and just as hard with someone else?

Ever been told to take it slowwwwwer? And do you believe there is a benefit to holding your love back and waiting?