You don’t have to break down Gödel's completeness theorem to understand the satisfaction around a feeling of “completeness”.
Many investors seek a sense of completeness in their portfolios.
That’s one of the many reasons why becoming a Boglehead or efficient-market purist is such a draw for the logically-minded. It lends itself in practice to such a nice set of practical steps that are either complete or incomplete.
Did we establish a realistic risk tolerance?
Did we translate the results of that risk tolerance to a low-cost, tax-efficient, market-cap weighted portfolio of funds?
Will someone rebalance this to keep us on track?
These are rock solid, and absolutely necessary questions for any investor to answer.
(Also, a computer can answer them, which is useful.)
However, my experience tells me that a set of logical questions with simple yes/no answers doesn’t “scratch the itch” for many investors: to have a conversation of substance about their investments & plans.
A few less logical questions that tend to help most investors feel “complete” include:
What investments are we missing out on?
What is everyone else doing that I’m not?
Are my investment people doing their job?
When is the last time I thought about this?
What’s the story here?
Completeness is relative. One strange attribute of financial planning is that it’s rarely, if ever, complete.
Many prospective clients ask if we can complete a “check-up” where we do the equivalent of a physical at the doctor, and that is quite useful. I try to let those people know that even though we can accomplish quite a bit in a short period of time, we may end up generating more questions than answers.