Sure, grandma may yell at you for using two paper towels instead of one, and then go on to give you a lecture about how tough things were in the Great Depression. (And for my younger audience, if you don’t know what that is please look it up)
Grandpa may tell you he started his first job when he was ten and wants to know why your fourteen year old son doesn’t have an after school job yet, even though the legal working age may be sixteen.
Don’t waste your energy arguing because you’re not going to change their minds. You’re not. And do you really want to get into a shouting match with somebody a heck of a lot older than you?
Look, honestly, there’s no reason to get upset. And you’re not wrong, either. You are both just products of a different time. Yes, Grandma grew up in a time when things were very lean and they had to make due with what they had. Yes Grandpa worked as a younger child but so did half his neighborhood…there were few labor laws and every dime was needed.
The best thing to do? Smile politely, thank them for their input and go about your business in a calm fashion. It is your life and how to live it is your decision:)