The Elderly: Are They All Demanding and Selfish and Undisciplined?

I thought it was maybe just my parents - I thought maybe as people get older it is harder to get what they want without the help of others (although my parents seem to have been this way their whole lives). But that begs the question: Why do they still take their wants and whims seriously at that age. Aging Care forums have multiple posts about elderly people calling their kids multiple timea a day, having demands, acting like brats, and treating their every trivial whim as some sort of crisis. Is this normal? Why does this happen? Wouldnt age release some level of wisdom to where the opposite would happen "oh look, there goes a want popping up in the mind again" vs. "OMG I need to be satisfied NOW and others need to make that happen. Waaaah!!"