This is very cool course

https://www.udemy.com/learning-python-for-data-analysis-and-visualization/

but it has very detail description of data visualization and very sudden and quick plunge to machine learning. The usual thing for a lot of courses: a slow and very detail explanation of simple things and then a sudden switch to speed and quite superficial explanation of hard topics. 

Maybe it's just because of my lack of math knowledge. Today I gave up and start to listen to statistics lessons of Brandon Foltz and in the middle of his lecture start to seek information about logarithms. 

This is really scary when I saw all this mountain of information and tons of lectures on the Khan.  I know that I shouldn't look too far and compare myself with other people, but this is very difficult to do. There is always some bad thoughts about the reality of my desire to work in machine learning sphere: Am I not too old for this?  Does my lack of math ok for this domain? Is it possible to learn all high-school and undergraduate math in realistic terms?

I have tried to do "beginner" course of Machine Learning. Actually, I have tried it already two times. The first time was some years ago and I gave up after the first hour of lectures. This time was a little better. I did not give up till the fourth week, but after the third week, I realized that I made tasks but didn't understand completely that I did. It was painful after four weeks, but I decided to quit the course till the better understanding of basics of machine learning.