When I started #improv, I never intended to perform. Just signed up for a class with @ImprovNeil having heard it was fun, and feeling like it might be a good life skill.
I always had stage fright growing up, even just for music recitals, so thought I'd never be able to do any drama or public speaking. (This seems very funny now.)
But the improv class was amazing, really freeing to start to be able to shut off my inner critic. It immediately translated to me feeling less anxiety at work, too, and getting a better perspective on failure.
That's especially valuable as a scientist, since we need to be able to come up with ideas but not get too precious about them: most experiments are 'failures' but we learn from them.
So when the course ended and we had the chance to do a showcase, I reluctantly agreed! And then had THE MOST FUN.
My improv course formed a group after our showcase, and we had an amazing run for a few years. I got really into #improv and met some amazing people, but also just had so much fun doing something creative and communal and freeing. 
I helped found @tightropedub, but then moved over to Galway for work... around the same time @BrightClubDub was taking off, which I don't think would have worked nearly as well without the skills and contacts I made in the improv community.
I'm very lucky now to perform as half of @jesssssimprov, with Jessica Keith who's based out in Kildare. We have a great time and we're really simpatico, you know? These are from a recent #improv show in Belfast:
In conclusion, #improv is extremely fun and a life skill and I think everyone should try it once.
