Some of us build walls, some of us become selfish, some of us work at changing any negative attributes that may have contributed to the parting or the cause of the broken heart. We tend to trust less and love less the next time around, as a defense mechanism. Why? The greatest feeling is to love and be loved in return. Why ruin that possibility because of a prior broken heart? Its a jungle out there - but to honestly love someone, and enjoy the experience of loving them is a beautiful one. If it works where the love is returned, (remembering that people express their love differently), then that is tremendous. If it does not work out that way, ten ride out the hurt, but thrive on the memories of one's love(s), and get out and about and not pine away in the house. It is most important to be receptive to the right one when they come around.
Love yourself. In doing so you must make great effort to mend your broken heart by enjoying your own company in many places, museums, beaches, the opera or anywhere. Be in your own space, and listen to your own voice. Love yourself and anyone else in the way you wish to love them, and love them as much as you want to.
Broken hearts mend. Otherwise, how could they get broken again? Date responsibly after the broken heart mends, and then love, love, love to the best of your capability.