“I don’t have time” is not a valid excuse for not writing tests or specs. It just means you don’t know what tests or specs are. Not having time to write tests is like not having time to hurry.
But “I have no fucking clue what I’m doing” is a great excuse for not writing tests or specs. Once in a while you write something weird that you haven’t written before, and sometimes when you do that, you need a messy sketchpad phase before you can determine what success will even look like. (After all, you can’t write decent tests without a good metric for success.)