[hallidayjb13]

You may have already come across it if you've read a lot of Stoic philosophy, but 'Meditations' by Marcus Aurelius is a good read.

Other books I've really enjoyed are: Talent is overrated, by Geoff Colvin (short version: working hard is more than half the battle)

Drive, by Daniel Pink (short version: to be motivated, you need to have/be working toward purpose, autonomy, and mastery)

How will you measure your life, by Clayton Christensen (short version: just read it - very good)

For the win - how game thinking can revolutionize your business, by Kevin Werbach and Dan Hunter (Note: one of the authors offers a Gamification MOOC on Coursera)

And for fun:

Eastern Approaches, by Fitzroy Maclean (short version: a pseudo-biography about a british man who was a diplomat, politician, and special forces operator all in one lifetime. Incredible)