Hands-on experience is how we grow and develop in our knowledge, skills, abilities, and perspectives. It goes beyond reading, listening, and imagining to immersing in the real thing. The information you gather during the latter is richer and more telling.
Training as an emergency medicine technician, shadowing, participating in research, volunteering at a free clinic, and other hands-on experiences during medical school are designed to introduce you to and prepare you for the work of medicine. Simultaneously, through these experiences you're trying on various aspects of medicine.
The earlier you identify which specialties and practice options you like and don't, the more time you have to continue exploring different options or to confirm the options you suspect you like. What's more, how you grow and develop during your hands-on experiences will be examined and considered as you apply for the next level of medical training (residency).