The most fun that I have had with C++ has been being able to make something out of nothing. For example, I can now create algebraic expressions out of some C++ code and have the computer do the work for me. This honestly was the most fun because I learned the foundations for what C++ needed to write complete programs and do certain things. This honestly made me excited because this poened the door for me to do other awesome things like create apps for a PC, maybe even write a game.