I recently worked my way through Walter Warwick Sawyer's book, Mathematician's Delight, which has opened my eyes to Maths. I used to fear maths, feeling I was incapable. Sawyer (among other authors) has a gift for teaching the subject. I now feel much more confident tackling Maths problems, I have a better intuitive understanding of Maths and a renewed interest in it.
There's a nice summary of Sawyer's life and work here: https://plus.maths.org/content/os/latestnews/may-aug08/sawyer/index
Have you had a similar experience after encountering Sawyer's work?