Okay first off birds are assholes. There is not a bird on this planet who is not a complete and total asshole. So if this is a missive telling people to live your life like a bird then I'm here to say don't. Don't live like a bird because birds are absolutely assholes, please don't be an asshole too.
Most people who feel like they are supposed to do something is not because they feel obligated by society. It's because they are unhappy and the things you are supposed ti be doing seems to lead to happiness. Some time they are some time they aren't.
But go find a truly happy person and they won't be talking about what they are "supposed" to be doing. The problem is that when people are not happy the obvious though is changing something in life to find happiness in it.
Every person I've known that has lived to 90+ have remained active and working in some capacity. Once they're no longer able to do that, they die soon after.
Spending your time making money for some company in order to buy things that have been shoved in your face as needs while also spending money on the commodification of actual needs is more of a mental disorder than trying to live small.