This is very true. I have a friend who is 83 years old and uses around 300GB a month. He discovered the joys of Netflix and Roku. I set him up with a DD-WRT router and couldn't get over how much bandwidth he uses.
By contrast I'm in my late 20s with a tech background and rarely use more than 100GB. I watch some Netflix but TV/movies aren't really my thing and the bulk of my online activity is web browsing and gaming.