Follow your dream. You’ll find out a lot about yourself in the process but don’t let the enormity of the task force you into thinking it’s not worth taking the chance. Sometimes your dreams will change. Sometimes what’s important to you will also change.
Allow yourself the time to make an informed decision with everything you do. If you find out that what you’ve been working towards isn’t quite the dream you’d hoped for then you can change. Unless you went on that path you’d never know what you like and dislike and so now you’re able to make a choice with substance. You won’t be thinking “what if?” but instead you’ll feel content about the choices you’ve made based on the experiences you’ve undertaken.
As always, don’t take things too seriously. We all slip up but be determined and give 100% of yourself to the task. If you’re not then you need to ask yourself whether it is even worth making the effort in the first place.