Do some shadowing in a variety of fields, look at the curriculums, get involved with medical related things. Honestly, we can explain it all you want but it will still only be an idea until you do it. Most people say they know it requires things like "hard work, dedication, and discipline", but the words are hollow until you actually run into those nights for real. Some of the most hardcore premeds I knew going into college are now accountants, lawyers, engineers, social workers, and a variety of other fields. The best way is to get exposed to every area of healthcare and witness for yourself. My experience wasn't exactly cheerful. I saw a 2 yearold boy die, a homeless person beat up by some kids, drug seekers and a morbidly obese man with some complications from gastric bypass amongst lots of colds and shortness of breath. That was my first day....You'll find it is either something that totally fascinates and captivates you or it is something you rather not deal with.
