Don't add it to your list, buy it and read it. Carry it with you. It helped me a lot. It's a great book because you can open it on any page and get a nugget of useful information. It starts with the title and then a quote by either Marcus Aurelius or another philosopher after which it expands on that quote with some context. There's some really good (and easily digestable) information in there. I earmark the best quotes and so far I've earmarked around 20 pages.