Do grades really matter?

When considering the question of whether or not grades truly matter in the grand scheme of things I initially found myself torn. I would like to think that grades do not have as much of an effect on me as actually learning the material the course covers. I would like to think that no matter how poorly I did, I would still enjoy the experience of being challenged. However, when I think about this in a real life situation I find that this is not necessarily the case. Last semester I took an Intro to Psychology class to find out if I liked the subject because I had never taken it in High School. I ended up learning a lot in the class and got an "A". I am now considering Psychology as a possible major and feel excited to explore different career paths in Psychology. Looking back on the past semester though, I have to ask myself, if I had not done well in the class would I be as excited about pursuing a future in the subject? Would the pure satisfaction of learning lots of new information make me as excited? This ideal that learning is all that matters would mean that getting a "B" or a "C" in a class would have no effect on me as long as I felt I had learned and retained useful information. As much as I wish this were true, it absolutely is not. If simply gaining knowledge would be enough to satisfy me, my academic life would be far different from what it is now.