When I mention doing it now - I'm talking about whatever you're afraid of. Many people don't like to do what they're afraid of because of the consequences or perceived consequences. Many people would rather simply do what's fun rather than what's necessary.
Epicurius taught about doing what's most pleasurable in life and many people do just that. Sometimes, people don't do what they need to because they just don't manage their priorities to include what they fear. Those are most of the reasons people don't do what they need to do when they need to do it.
For whatever the reason to procrastinate, there are costs to doing so. In relationships, a significant other can become angry, disappointed and/or lose trust in you. In health, procrastination can cause obesity, high blood pressure, high cholesterol, loss of mobility and general poor health.
In self-esteem, it can lessen how you feel about yourself and your self-trust. At work, you could get demoted since you're not as reliable. WIth friends, you could lose them since they want someone they can rely upon. WIth plants and animals, they could die or be seriously maimed.
On the other hand, if you learn to do it now, little by little, things will get better. You will start feeling better about yourself. Your friends and family will know on you they can depend. Your boss will possibly give you promotion for being so responsible.
Basically, people don't do it now because they'd rather do what they want to do rather than what they HAVE to do. In relationships, healthy, work, and self-esteem, NOT doing it now really can cause damage. On the other hand, doing it now can slowly but surely improve your life.
It sounds too simple for your life to be that much better for simply doing it now. It's not easy to keep all committments. Yet, little by little, things will get better. I'd love to hear how doing it now helps YOU.
Life/ Corporate Coach