Some people gesticulate? I've noticed older people do it more while taking but what purpose does it serve? Also if someone is having a heated discussion the gesticulation tends to be more wild lol.
It's not confined to older people, IMO - but then younger people so often have their hands full of phones, takeaway coffee, bottles of Pepsi..... I find it very useful to help to express myself with my hands, it's an extension of facial expressions.