Decisions Determine Destiny 

I think that this quote mean that every single decision determines your destiny. So if you choose the wrong that would be you decisions and that would determine your destiny but if you would choose the right that would be a good decision and determine a good destiny. For example if you drop out of school than you would have a not so great destiny because you wont have an good job but, if you would work hard and stay in school and study hard  you can have a great future ahead of you.