They say experience is the best teacher. But even better is learning from other people’s experiences—and one of the most effective ways to do that, behavioral scientists have found, is to reflect on their regrets.

By regrets, we mean powerful negative experiences associated with deep sadness, disappointment, or even shame. You might be surprised how many highly accomplished leaders harbor such feelings.

A 2023 international study by Oracle and author Seth Stephens-Davidson, for example, indicated that some 85% of business executives suffer from “decision distress—regretting, feeling guilty about, or questioning a decision they made in the past year.” Perhaps that helps explain the unusually high number of American CEOs who resigned last year.

The Behavioral Sciences Lab at Boston Consulting Group, my employer, recently asked a group of about 70 former CEOs, C-suite executives and board chairs from a wide range of industries to tell us what they most regretted during their tenures, and to rank how intensely they regretted these situations.

There are two basic types of regrets, those of “commission”—I’m sorry I did something—and those of “omission”—I’m sorry I didn’t do something, or did it in a certain way. More than 60% of the responses we received were of the latter type.

Overwhelmingly, C-suite regrets fell into four categories. Respondents said they regretted that they hadn’t (1) moved faster and more boldly, (2) built better teams, (3) fostered deeper relationships, and (4) been truer to themselves in making decisions.