• There's something powerful about knowing an end exists
• Having a particular end date where things will supposedly become easier means being able to convince yourself that you can push through that number of days
• If our initial conviction was that things will now be easier - automatic even - when we hit a particular date, we'll be quite disappointed when things remain hard

In a famous book from the 1960s, Dr. Maxwell Malt said: "These, and many other commonly observed phenomena tend to show that it requires a minimum of about 21 days for an old mental image to dissolve and a new one to jell."

21-days seems reasonable. Easy. Tweetable. Doable. Pretty much everyone can persist in doing something for 21 days.

• Your value system takes a drastic turn when you keep practising an activity you want to form as a habit.
• Embarking on a habit-formation journey gives you the opportunity to figure out what you really value.
• Persisting in doing something allows you to see which things are important to you.

• The essential thing is figuring out what tasks are worth keeping and what aren't.
• When you stick to a certain activity for 21 days or more, you give yourself the opportunity to find if this new thing is valuable enough - for you - to keep doing it.
• Regularly hitting the gym allows you to see how this activity can positively impact your body, mind, and life in general.