Just as a virus is constantly adapting as the immune system tries to defeat it, the change movement must learn to evolve. Being wedded to the form that lead to early success is a sure route to failure. Unless the change effort mutates to fight the organisational anti-bodies its legacy will be nothing more than a sense of what might have been. You may not be able to plan in advance just when or how you will need to change the way you change, but you need to be very aware that at some point you will have to. What you end up with may not be what you first envisaged, but it will be real and lasting.