Promises

We say times change and so should we, but what about the promises that we make.
Are they bound to eternity or do they change their flavors with time?
Are promises meant to be broken?
Is making a promise a temporary thing in life?
More often I see that we end up keeping promises that have a short life span and we keep them up with the same enthusiasm sincerity and willingness, where as, those which are made for years on stretch like in marriages, over time becomes like a thorn in the throat. This I think is probably because the promise looses its true meaning.
So I feel if one makes a promise they should remember and it is equally important to renew it. Failing to do this is what creates room for assumptions, disrespect, miscommunication, misunderstandings, and one never finds the other person special enough (they take each other for granted). So promises by itself are never for life until we work on it.