Just an offer to discuss:
Read the definition of the legal term "pledge"
http://legal-dictionary.thefreedictionary.com/pledge
Often we are the only signatory on an "agreement". Could an offer have been made in general to the public? Or a privilege offered to anybody inclined? And we accept the offer by signing and pledging our acceptance and agreement? We step in voluntarily to the resultant "obligation", and from that point forward it is no longer voluntary, but we are now obligated? At least until we rescind or terminate?
If one no longer is obligated, is he obligated to maintain records of his previous obligation? I think not.