No. What's the worst that happens? You take longer to do the challenges?

The leaderboard is irrelevant, as you can only get on it if you're in the right time zone/nocturnal/unemployed and really really fast, so what you then get out of it is a solid set of Haskell problem-solving skills.

People learn languages in AoC every year. Do it!

Some people do each day in a different language. Maybe don't do that...

I went into ICFP 2007 with two other dudes, only one of us knew Haskell (not me), and yes, it was a death sentence.

However, ICFP is 4 days, not a month, and the experience was good enough that it made me want to actually learn Haskell properly. I had fun and benefited in the long run. :)

I was most of the way through last year's in C# when I decided now was the time to properly learn (algorithmic programming in) Elixir. That set me back in terms of speed, but it was well worth it. I'm now fairly fluent and I'm doing this year's in Elixir from the start, so - yes, it's a great way to get into a language, I would say.

I used last year to learn Elm really well and plan on using this year for F#. Go for it!

Elm served as a gentle intro to Haskell for me personally since it has easier to read errors and less overall complexity to grok at first go, but it sort of depends on your experience.

Well, I've used previous challenges to learn/improve my Nim. And I can tell you, after solving whole 2015 challenge - my Nim skills have noticeably improved.

Would recommend AoC as a learning tool.

I found Project Euler really helpful for learning new languages, I imagine AoC is similar.

just do it, what's the worst that could happen?