So in my class we joked a few times about how "Improvise. Adapt. Overcome." was important. But it's really not a joke. Adaptability is key. Right up there at the top I'd also rank being able to study the scope quickly and accurately as a top skill. It took me a while to really build that up, but once it got better I noticed I stopped running planes into other planes and airspaces as much. And the only way to get better is to make sure every practice ERAM you get better at something, even if it's just one facet of your whole job.
It's a rollercoaster. It's not so much that everyday is the hardest thing I've ever had to do, it's that I've never had so much pressure driving me to try and succeed over such a length of time. It really begins to drain you, which then affects your ability to learn and demonstrate what you learned - which then stresses you out because you think you suck and the clock is ticking until evals. I fully believe one can overwork or over study. If you dont have effective methods for unwinding and grounding yourself, find out before you get here.