How big is your Calculus? or go Matan yourself!

I have been kinda reading somewhat about programming lately, like for the last year or two.
And often when i noticed the discussions going far in to the, now kind of trending, functional land,
or sometimes when discussion was going even deeper (you see the trend there), i have seen calculus being mentioned. I always asked myself what the heck is this Calculus thing they are talking about. Its not like i'm totally math illiterate. Back in Russia 15 years ago i almost finished secondary education. Which means we have studied sines, cosines, tangents and cotangents stuff. (trigonometry apparently, like i even remember right..).
But then i ended up in Belgian public school, where we were studying worst programming language of all time, which was worst school i have ever been to. I couldn't understand anything. Maybe because it all was in Dutch. Or, i just discovered this, i have no words what i feel now.. o.O For years, after this C++ and boolean algebra failure, i was thinking Europe was so advanced i maybe wasn't smart enough.. But hoorah to the new math. And Cpp madness.
But ok now. When i finally found out that this Calculus thing in Russian is called Matan - and started reading about it. I discovered words i have already been hearing from my mother for years. Like integrals and differentials. When she was romanticizing how she was studying it at the University. (Immanuel Kant's University).. And this article actually really explained quite some stuff about it to me.

I also just noticed that it is also about Lambda Calculus actually, rather than about just Calculus. But after i just formed the scheme for myself that i had lessons of trigonometry and that is something on the level before the precalculus. This is already enough for me to at least know where im standing. The rest doesnt matter. Im not planning to be a mathematician in the near future.

Maybe this guy is actually right, because as soon as i decided to leave and dont care anymore about this failed Microsoft Academy i have been spending a lot of my free time at and for, last few years. And maybe just do an online Linux course or even better some WebDev stuff. I started to discover a bunch of interesting stuff.
Or maybe im just going mad right now..
p.s. Common Core the Billy talks about has something to do with this new math to.