Those who do not remember the past are condemned to repeat it.

Those who cannot remember the past are condemned to repeat it without a sense of ironic futility.

Those who disregard the past are bound to repeat it.

Those who cannot remember the past, are condemned to repeat it.

We must welcome the future, remembering that soon it will be the past; and we must respect the past, remembering that it was once all that was humanly possible

Even if we remember the past, odds are good we'll still repeat it.