I heard this from a senior colleague of mine that he's been working through the book "How to prove it: A Structured Approach"[1] that show how to prove things in mathematics, and has quite good exercises.

Perhaps a hands-on approach such as solving the exercises while working through this book will prove beneficial and is complimentary to watching, say, KA or 3B1B.

[1]: https://www.amazon.com/How-Prove-Structured-Daniel-Velleman/...

Just wanted to say - you've got giant balls! Going back to school after 9 years - I believe is no small decision. I wish you good luck!

I've been toying with this idea for a while, but haven't able to take this step for various 'excuses'(not enough money ~atm).

Would you mind sharing what went through your mind to finalize this?

What factors influenced you(made-your-money? unemployment? ..??)

Have you already finalized your specialization? Has anyone influenced you in choosing your subjects?

finally, What are you doing for math-prep for CS classes?

fwiw- 'how to prove it' -velleman has helped me to some extent. (http://www.amazon.com/How-Prove-Structured-Daniel-Velleman/d...)