"I know stocks can be a great investment, but I'd like someone to manage the process for me." You may be a good candidate for a robo-advisor, a service that offers low-cost investment management. Virtually all of the major brokerage firms offer these services, which invest your money for you based on your specific goals. See our top picks for robo-advisors.

What would make me sell: Sometimes there are good reasons to split up. For this part of your journal, compose an investing prenup that spells out what would drive you to sell the stock. We’re not talking about stock price movement, especially not short term, but fundamental changes to the business that affect its ability to grow over the long term. Some examples: The company loses a major customer, the CEO’s successor starts taking the business in a different direction, a major viable competitor emerges, or your investing thesis doesn’t pan out after a reasonable period of time.