The best investment is in the tools of one’s own trade.
最好的投资是投资于自己的事业。
You can obsess about serving your customers/audience/clients， or you can obsess about beating the competition. Both work， but of the two， obsessing about your customers will take you further.
The stream of thought is a stream of life-preserving adjustments.
Always look at what you have left. Never look at what you have lost.