For some of us, telling the world that we are finally going to get healthy is a good thing because it holds us accountable and forces us to succeed.
For others, having to live up to the pressure from other people along with your own personal pressure can use too much of the energy that you should be focusing on achieving your goal at hand (not making others happy) and ultimately sabotage your goals. So if you find yourself identifying with the latter, then you may just want to keep your goals to yourself in the beginning so the pressure is not coming from all directions. Nothing is worse than when you're already feeling guilty about skipping the gym and your coworker goes, "Off the wagon, eh?" Trust me, I know.
Does this resonate with you or are you happy letting the world know you're planning on losing 15 pounds in the next three months?