Even the most self-reliant of parents can grow ill or infirm, becoming dependent on a child. Indeed, the more independent the parent is, the harder it is for the family and friends to believe in the parent's uncharacteristic incapacity. The parent's need for help can happen gradually or overnight. The more gradual the decline, the easier it is to ignore or deny. Setting up specific markers for estimating abilities, such as balancing checkbooks or remembering medications, can help you judge your parent's need for aid with some degree of realism.
Parents may not realize, may ignore, or may deny their new neediness. If they are aware of it, they may well be embarrassed, even humiliated by their situation. Nevertheless, once parents begin receiving help, they will expect that assistance to continue as naturally as they expect to breathe oxygen. And they will be generally just as minimally conscious of the help as they are of oxygen.