I do have a strong belief in the desirability and necessity of being a life-long learner - have to keep things interesting. I think the easiest habit discussed in the online video is number 2 - to accept responsibility for your own learning. No one else is going to insist you keep growing, learning, improving. So if you want to continue to be interesting and useful, you better know that you need to take that on for yourself.
The hardest habit for me? Probably to view problems as challenges. Sometimes, problems just feel like problems. On my good days, I do see them as challenges and even have fun jumping in to fix them. But there are plenty of days when problems just seem like problems, and I want them to go away and let me do something easy!