What is This?
"How can smart people so often be wrong? They don't do what I'm telling you to do: use a checklist to be sure you get all the main models and use them together in a multimodular way". 
Good investors have a general framework for what kinds of investments they want to make. Great investors have a checklist to make sure they don't forget anything. That may sound overly simplistic but the smartest people recognize that they won't always think of everything and they need a process to keep them in check.
"Firefighters have to check their gear and make sure pumps are in working order. Pilots have to do systems checks every time they fly. Surgeons have to make sure their instruments are sanitized and neatly laid out before surgery. But when it comes to knowledge work, we act as if preventative maintenance isn’t required." (Tiago Forte)