I was. But (a) a lot of things are subsidized as a grad student, and (b) savings are nearly zero. It's close to a paycheck-to-paycheck life unless you have some external income (which I did, via Google Ads that I slapped on a 250K MAU/month website of mine).

I'd consider "being able to save enough to continue a modest quality of life for retirement" a normal feature of what describes middle class life.

If you are living paycheck-to-paycheck you'll suffer when you hit old age or have a disabling condition that prevents you from working.

Thanks for a detailed response. I'd definitely like some extra income as a grad student, but I cannot earn outside of the university because of my visa restrictions. For all intents and purposes, you may as well consider me living paycheck-to-paycheck. I wish academia paid better.