'Too much free time won't make you happier,' says psychologist

I think one thing studies like this miss is that it’s ok to have above average workload(e. g more than 40 hours), as long as you sprinkle in 1-2 weeks complete rest.

About 8 years ago I suffered from severe depression and burnout - I quit my job and basically spent 6 months browsing the web and smoking pot. My burnout was caused by overwhelming work without direction and terrible office politics. That is when I discovered that I’m the happiest with bursts of high productivity for 2-3 months with longer than average time off(2-3 weeks). Now I haven’t been working for 2 months and I’m craving that high workload again

Edit: Sorry for going on a tangent, but work-life balance has become important to me. What eventually led me out of my stress induced depression was a friend offering me work - it was a couple of levels below what I was doing before, I want from being a supervisor to doing fairly hard labor I had been supervising. It gave me a fresh look at my work life and a couple of years later, I had well surpassed where I had been in my career wise before my breakdown.

Another thing: just because you’re working 80+ work weeks, doesn’t mean you can’t have a social life. I met my current girlfriend while working on average 70 hours a week for 12+ months.

My point I guess is that these hours/day can be shifting quite a bit. Sometimes you need a maximum of 5 hours per week and sometimes you’re going for 90, and both are OK. We’re all different at different points

Only because most haven't figured out what happiness is. If happiness is being in control of your limited time here, than giving too much of that away in exchange for material belongings amounts to self torture. Find your balance, and do it sooner rather than later. If you put it off, work has a nasty way of taking control.