When you are creating your own brand and are trying to build your own long-term business you need to put emotion in your investments. You need to create something so powerful that other people are going to be emotional about it.

Short term there are marketing timing and arbitrage opportunities, but to create something that will be sustainable and grow it helps to put emotion into your work.

When you are investing in other companies (with money, for example) then it helps to leave emotion off to the side and invest without it.

Be irrational when investing in yourself. The market will never predict your success because they don't know how much you can do. If you push hard enough you can even create your own markets. But when you are investing into someone else's business don't be emotional about it, at least unless you are truly getting in at the ground floor.