Is calculus really hard?
Calculus will have concepts that are simple, but it will also have concepts that are difficult to grasp. Calculus 1 is pretty average in terms of difficulty, but once you get into Calculus 2, which basically consists of learning all the ways to solve integrals, the difficulty certainly goes up. Then there is Calculus 3, which I personally found to be a lot less stressful than Calculus 2. In the end, it all comes down to you, and how motivated you are to cross the finish line. I would not say it is “really hard” but it can certainly be a challenge sometimes.