Sorry, I strongly dislike both "Work harder" and "Never give up". How hard is hard enough? When you're burnt out? Or even harder still? And why _never_ give up? What if you're "not giving up" pursuing a wrong thing? If you "give up" and start pursuing the right thing, why is this bad? What is "giving up" anyway. Not sure if trivializing these questions is necessarily productive.
Never give up.
Nothing to it but to do it (Ronnie Coleman)
The journey is the reward (I think this is Steve Jobs)
What can I do to move myself towards my goals right now?
These are things I usually say to myself throughout the day.