In his own words · Circle of competence
“We have three baskets for investing: yes, no, and too tough to understand.”
— Charlie Munger · Attributed to Munger; Berkshire/Wesco meetings
As recalled from Attributed to Munger; Berkshire/Wesco meetings — the sense is right but the wording is not verbatim.
Frequently quoted from the Berkshire and Wesco meetings; wording varies.