Please let me know what programming language you don't need to learn to use. I have frequently been able to debug or explain unexpected behavior in programs wr

Please let me know what programming language you don't need to learn to use. I have frequently been able to debug or explain unexpected behavior in programs written in languages I had never used before. Javascript, C#, Python, windows shell scripts, PHP, ASP, Emacs Lisp, and Visual Basic 6.0. Common Lisp, C, and bash are the only languages I had to really "learn" before I could read code. Perl is the only language I feel like I have to re-learn every single time I have to read it.