Python, coming from C/C++, Javascript (at least circa 2003) was like leveling up 10x in my programming superpower. I was able to explore concepts and domains so much faster, and those concepts have led to my career. I've talked with friends who only know something like C# or Java, and I feel bad for them - they have no language in which to rapidly play with things. And that rapid ability to play (like with the Python REPL) makes a huge difference in learning.