3blue1brown, all of his stuff is really good, it visually grounds behind the scenes intuition on the memorization stuff we all were taught (chain rule, power rule etc.). I wish I had this when I took these courses.

Essence of Calculus -
https://www.youtube.com/playlist?list=PLZHQObOWTQDMsr9K-rj53DwVRMYO3t5Yr

His essence of linear algebra series is also very good -
https://www.youtube.com/playlist?list=PLZHQObOWTQDPD3MizzM2xVFitgF8hE_ab