When you hit med school.
I'll admit, I'm not done with school yet but keeping a 4.0 is possible with the right precautions. I consider myself risk averse is some respects because maybe I am apprehensive to bite off more than I can chew. But why would I sign up for a harder professor when there's a more lenient one available, for example?
I'm a chem major, and I know that once I hit classes like Physical Chemistry, I don't know how well (or how badly) I'll do. So for now, I set myself up in a very good position (high gpa) to prepare for any future obstacles. If I overcome those obstacles, great, but If I take a few Bs or potential Cs, my "safe" decisions I took now are going to balance it out.
I would encourage you to not just play it safe with an expectation that one day in the future you'll cut loose and challenge yourself. Habits have a way of hardening and becoming quite difficult to shake.
As far why you'd sign up for a harder professor, do it because it'll push you to work harder and learn more. When I was a freshman, a (brilliant) upperclassman friend of mine was bemoaning the difficulty of the notoriously tough modern algebra sequence. It was widely agreed to be, he told me, the hardest math class at the institute. I immediately knew I'd have to take it. Several years later, I did. It was, as advertised, very difficult. The professor was a great teacher, helpful, friendly, cogent, but he expected a lot from us and the material was, in fact, highly abstract and very, very challenging. I worked hard. I contorted my mind into all manner of bizarre shapes. I spent countless sleepless nights, desperately trying to find solutions to the problem sets. I learned so much, and I honed my already pretty good analytical skills to a razor sharp edge. I had a blast. And in the end I earned a B in both semesters, which I considered to be a fine showing.
I did that because I'm the kind of person who sees a challenge and immediately wants to step up to it. Because I don't look for the easier professor, I look for the _hardest_ professor. Because I'm not afraid to take risks. Because I want to be all I can be.
I'd encourage you to reconsider your priorities. Do you really want to go through life looking for the safe, easy route, telling yourself that some day in the future will be the time that you actually challenge yourself and start living for real? Or do you want to push yourself to your limits?
