I think that if you're serious about achieving that goal, you'll do whatever it takes to get there. But, if you simply have a shallow goal one where you heart is not that involved into it, you will not get far. Laziness, discouragement, procrastination, and demotivation will be allowed to slip in which in turn will ruin your weight loss goal. I would suggest you to start off by giving it your very best because at some point you will cross a threshold in which there is no turning back.