When I first started programming, this would have been about 2009.
Everyone said python was slow, learn C++. So i did. I never taught myself python until much later. Huge regrets. All of my open source projects are now in python.
I've discovered there's literally only 1 thing in python that causes it to be slow.
Global Interpreter Lock.
Use multiprocessing and avoid this problem? Now python is as fast as I ever need it to be.