Ciro Santilli These videos can give some geometric insight and do have their value.
But they are sometimes too slow, there are never any mention of experiments, just "the truth".
And when things get "mathy", it sticks to a more qualitative view which may not be enough.
Very over the top with sexy demons and angels making appearances, and has some classic aesthetic artistic value :-)
Eugene's background: www.quora.com/Who-is-Eugene-Khutoryansky/answer/Ciro-Santilli