Very Short Introductions
veryshortintroductions.com
veryshortintroductions.com
Lenny's book is an absolute gem for anyone working in statistical modeling, time series analysis or prediction of any sort.
Every ML engineer should read it and weep.
EDIT: I agree with the comment that the series is inconsistent, due to the length. I find that more niche topics are treated better than the surveys of huge fields (like "Philosophy").
I have three books (Sound, Waves and Mathematics) from this series which are pretty good.
The entire series could benefit from more editorial oversight so that the books have consistent information density, tone and writing style.
I disagree here. Wikipedia just bombards you with data and does not lead you by hand into understanding; /r/ELI5 is trivial and mostly cutesy-poo writing.