The name never comes to our imagination until we clear 10th Boards.The moment we enter 11th class or Intermediate of Science the words pops up from nowhere and haunts us like nothing. Every student had this ordeal in their own way. Same was my case too when I was at your age.There were moments of despair, moodswings.
Calculus once understood it makes everything seems easy and we become the winner.The question still persist what exactly is Calculus.What ever we studied till 10th was just the basic mathematics.The real maths comes to picture only when we consider everything around us to be infinitesimal.Calculus pokes us to imagine things,question them and the real logic comes to picture.The entire philosophy of Calculus is to develop creative thinking. We start seeing everything around us with a question mark.
The first thing what worries a student is Differentiation.There was no clue what the heck is this.We were the brightest in our class but nowhere this thing existed in Maths. dy/dx worries us more and we are being told everywhere this is differentiating the variable y with respect to the variable x. d/dx is the derivative of y,where y is a function of x (y is a dependent variable and x is an independent variable) or in other way the the rate of change of y with respect to infinitesimal change in x. The tangent or the slope of y at x gives is dy/dx.
Hence, concluded.