That seems to be a common question on the various threads so I thought I'd start a thread all about just that!
I am an online media specialist. My training is in graphic arts and digital layout and I've expanded from there.
I actually received my degree (What's called an Associates degree in the US, where I earned it. Not sure if there is a UK equivalent. Maybe a qualification?) over 20 years ago, on top of a BA in Theatre Lighting Design. And then didn't use it except here and there and to keep my hand in for a good chunk of those 20 years. I was in California at the time and on every street corner there was an other GD with a sign 'Will design for food.' 
So I became an admin assist to pay the bills. And kept doing that until I worked my way up to Personal Assistant to Vice Presidents and CEOs.
Then I moved to Belfast and was hired as PA to the CEO and Chairman of a very small company. Who need web and graphics help as well. So I wore both hats.
Then I left to have my son. And knew I didn't want to go back to work full time. So I sent a proposal to my boss suggesting they bring me back part time and flex time, as their web person.
He counter offered with "Why don't you resign, start your own business, and we'll hire you."
And I said "GULP! Okay!"
And Designed To A Tee (Named by a fellow MNetter, BTW) was born. NOTE: Website needs a huge update. The Web Designer has not time to update her own site!!!
Finished my second year in business this past April. I have several long term clients and have had one or two one offs for logos and such. Thanks to nearly no overhead (I work from home) I made a profit, albeit a tiny one, my first year.
So my story is unique in that I already had the training. But that doesn't mean someone else can't be success by retraining right now!
Okay...what's your story?