12 years is a long time, you have the opportunity to be able to have more important things, at least you will not only try but also to prove that you are 12 years old together with other people's companies have given a lot of opportunities, capabilities and is also a friend.
I think life is not just about the results and benefits, life needs a purpose, as well as build a future, not just calculate profits and results that you can be in front, but the purpose of what you have achieved.
about the reasons, the world is spinning is not without reason, as well as your life, surely there are a lot of reasons, 12 twelve years of working with the owner of the company is to be a reason for you to begin a new purpose, but there are many other reasons, and I believe is one of them is, you can prove that you can do something more for the community.
you should really expect what is in the future, but it would be much better if you start to seriously set the purpose and goals, and I believe the advantages and the results will follow you.