Motivation
Working out and not working out are two completely different lives.
Fitness or non-fitness is a choice, would you choose a life of fitness or a life of non-fitness? The sooner you start working out, the sooner you will reap the benefits of fitness.
When you first start working out, you may not feel much difference from people who don't work out, but when you stick to it for 3 months, 6 months, a year or 3 years, you will find the difference between working out and not working out, in increasing spikes.