After you've chosen
Most advice about decisions stops at the choice. For someone with this habit, the choice is only half of it. The day after you choose is when the loop tries to start again.
The first thing to expect is the wobble. It usually comes within two or three days, often at night. You've sent the application, and suddenly the builders' merchant seems warm and safe, and the other firm's extra three thousand seems like money you've thrown away. People buying houses and cars know it as buyer's remorse. I think it's the same doubt that followed whichever option was ahead, in chapter 9. Now that one option has won, all the doubt goes to it. The wobble doesn't mean you chose wrong. You'd have felt it whichever way you'd gone.
So decide in advance what would count as a reason to reopen the question. Only a new fact counts. If the college cancels the course, that's a new fact. So is your firm announcing redundancies, or your partner's hours changing. A bad night isn't a new fact, and neither is an article you happened to read, or a friend raising an eyebrow. It helps to write the rule down on the day you choose. "I'll reopen this only if one of my musts turns out not to be met." Then, when the wobble comes, you have something to check it against.
Second, close the other options properly. Chapter 8 explained why. While they're open you'll go on comparing, and while you compare you won't settle. Delete the bookmarks and unsubscribe from the other firm's job alerts. Put the fabric samples in the recycling. Move the spreadsheet to a folder you don't open. It can feel wasteful, even a little sad, to put away fourteen months of work. It did its job as far as it could. The closing may be what lets you start liking what you chose.
Third, tell people. Tell the ones you consulted, in a sentence, without asking what they think. "I've applied for the course. I start in September." Saying it aloud makes the decision harder to reverse quietly at two in the morning. It also lets everyone stop waiting with you.
Fourth, put the effort where it now belongs. Chapter 6 argued that a good part of what makes a choice right gets added afterwards. The hours you used to spend on laps are free. Spend some of them on making the choice work. Read the first book on the course list. Work out the budget for the fees. Sit on the new sofa and watch a film.
Finally, set a review, once, at a sensible distance. For the course, that's the end of the first term. For a job, six months. On that day you're allowed to ask whether the choice is meeting your musts, using what you've learned by living it. That's the information you couldn't get beforehand. In between, the question is closed. Most people find that by the review date they've half forgotten it was ever a question.