First of all, it's important to understand that there really isn't a correct answer to this question. It's more or less just important to ask yourself so that you know the actual reason you're signing up for at least a few years of study. Predicting where you will be in 5, 10, 20 or even 50 years, as well as what will occur between then in your life is virtually impossible. Perhaps down the track an investment will pay dividends or an inheritance will fall your way giving you some financial freedom to do something else with your life, something that you may have wanted to do for some time however haven't had the means to do so. While speculating is risky, at least ask yourself before you commence any degree the actual reason you're getting yourself into it.
2) Is this what I genuinely want to study?
Fresh out of school at 18 is admittedly a tricky time to determine your career path. Some of us have known for almost a lifetime the path they've wanted to follow, however for others uncertainty has always existed. Choosing a degree on a hunch is always a risk and if you're like some of us, your interests are constantly changing which occurs especially often once you have completed school and have the world at your feet. Take your time and deep breath, talk with your parents and friends. Listen to others, however remember that the decision ultimately lies with you.
3) Is the timing right for me?
As mentioned earlier, taking the step straight from school into University is a big leap. Admittedly, the same thing could be said for embarking on something along the lines of a gap year, however when you're young, fit, healthy and importantly optimistic, it makes sense at this time in your life to see and explore the world. You will undoubtedly have peers tell you that you'll never go back to study after holidaying and partying for a year, however while it's not for everyone, should you have the opportunity to do it, at the very least consider it!