There’s an old Yiddish expression that rings true far too often in life: “Man plans, and God laughs.” The obvious meaning is that we all try to plan how our lives should unfold only to discover how much we don’t control.

When you’re in the business of financial planning, certainty is rarely an outcome. If someone were to retire with $10 million in investable assets, for example, while spending $50,000 per year, we could say with (almost) absolute certainty that they will never outlive their money. The truth is, however, that most of us have fewer assets, spend more each year, or some combination of the two. Thus, for the rest of us, the outcome of our financial plans falls into a range of probabilities.

Many investors think they have sufficient knowledge to time the market despite the overwhelming evidence and compelling story to the contrary…Picking stocks is more like gambling than investing.