Followup to: The Bottom Line
A recent conversation reminded me of this simple, important, and difficult method:
When someone asks you "Why are you doing X?",
And you don't remember an answer previously in mind,
Do not ask yourself "Why am I doing X?".
For example, if someone asks you
"Why are you using a QWERTY keyboard?" or "Why haven't you invested in stocks?"
and you don't remember already considering this exact question and deciding it,
do not ask yourself "Why am I using a QWERTY keyboard?" or "Why aren't I invested in stocks?"
"Should I do X, or not?"
Should I use a QWERTY keyboard, or not? Should I invest in stocks, or not?
When you finish considering this question, print out a traceback of the arguments that you yourself considered in order to arrive at your decision, whether that decision is to X, or not X. Those are your only real reasons, nor is it possible to arrive at a real reason in any other way.
And this is also writing advice: because I have sometimes been approached by people who say "How do I convince people to wear green shoes? I don't know how to argue it," and I reply, "Ask yourself honestly whether you should wear green shoes; then make a list of which thoughts actually move you to decide one way or another; then figure out how to explain or argue them, recursing as necessary."