Hi!
Only doctors on the left can take 3 patients. The game doesn't save your progress but you can use the commands from the help menu (pressing H) if you want to go back to this level and finish the game.
Ohh I see. I thought only if they were tired they can only take one. Even if they're not tired on the right side they can only take two?
Okay so the last level is unbeatable to show that doctors are overworked? I think it's cool that you embedded a message into the puzzle!