I did financial plans for people decades ago, and usually, those that did reach their goals did so not because they bought mutual fund A instead of mutual fund B, or this investment over another, it had to do with having the right behavior and keeping the big questions in mind.
Ben Carlson wrote an absolutely wonderful blog that I’ve linked to below. He says very succinctly what I say all the time, and truly believe.
Here’s his list of 7 Simple Things Most Investors Don’t Do
Look at everything from an overall portfolio perspective
Understand the importance of asset allocation
Calculate investment performance
Save more every year
Focus only on what you control
These are absolutely right on, and reflect my thinking.