At one point in my career, I've been a CTO of a startup company. I worked 12-14 hours a day, including weekends. My relationship with the CEO was bad, and he actively added "senior tech leads" to the company to compete with me.

One day, I arrived to the office, and stood in the hallway across our office door. I froze. I couldn't physically move. I stood there, unable to move, for 2.5 hours until someone passed by and saw me.

I'm sharing this story so that readers may have an idea of what severe burnout may look like. It's not that I didn't want to move - I couldn't, my brain didn't let me. I lost my ability to control my body at that point.