For the #mathematics inclined or merely #math curious, I've been really enjoying 3blue1brown's youtube channel recently.
https://www.youtube.com/channel/UCYO_jab_esuFRV4b17AJtAw
His two "Essence of..." series are quite good.
Essence of Linear Algebra: https://www.youtube.com/playlist?list=PLZHQObOWTQDPD3MizzM2xVFitgF8hE_ab
Essence of Calculus: https://www.youtube.com/playlist?list=PLZHQObOWTQDMsr9K-rj53DwVRMYO3t5Yr