I used C++ to write an artificial life simulation in the 1990s. Then in 1998 I discovered Python and didn't look back at C++. Python unleashed a joy in development for me.
Fast forward decades of experience and maturing.
Now I know Rust, which I enjoy using as well, and whole fields of software development that I left behind with C++ are opening back up.
This is Mur 
@faassen
You should also try Golang, very simple and nice like python
@mur2501
Amusingly enough I have avoided Golang for that reason. I already have Python for simple and nice.
I wanted to learn a language that challenges me to think differently, and have a true systems language in my toolbox. I am sure Go is great, though.
@faassen
For stretching the programming muscle I think Lisp, Haskell, Erlang, Ada, etc would give a very fresh and new look into programming
@mur2501 Rust stretched my programming muscles, for me. I've used Haskell for a little bit too, and dabbled briefly with Lisp a long time ago. Erlang is definitely interesting (or Elixir).
I'm not sure what Ada would bring to the table, could you elaborate?
Stack languages like Forth, APL-style array languages and Prolog also stretch muscles.
@faassen
Ada brings strictness of design generally.
@mur2501 I realize it's not a photocopy of Python. I just haven't felt an inclination to add it to my toolbox as I was looking for something that stretches my programming muscles. I'm sure Go is great though!