I say "learned" here because we don't always use every language we learn. But, what is the most influential languages you have learned? Why was it influential? Is it the language you currently use? If no why not?
For me this has kinda been in 2 stages. First when I was new I started with PHP. and after knowing it and using it in a job for some time, i started learning C# on the job and helped with it. It was eye opening. Mostly because I learned more about how languages like PHP worked "under the hood". It was like a cover was lifted. But to this day, I never really took use to it full time or for my own uses.
After that, I started playing with python a lot more which is mostly what I use today along with PHP.