And since the most common question I've been asked in those years has come from some full-timer or other sidling up to me and whispering "I'm thinking of going freelance, what's it like?", I thought I would start there.
Before I do, you should remember - your mileage may vary. I think I've been very lucky. I've certainly been largely incompetent managing my freelance life. And the very fact that I'm giving it up, at least for a while, should tell you something.
But, I have to say, I've loved it. This is the good news.
It's a tremendously liberating, enlivening experience - simultaneously shedding responsibilities and gaining control of your own destiny. I remember the first time I was able to stand in front of a client and offer advice without a voice in the back of my mind muttering: "Say the wrong thing and we lose the account and have to fire 15 people."
I could just say what I thought, what I meant, and the only job I was in danger of losing would be my own.
I've also spent more time with my son and my family than I could have hoped for if I'd still been climbing the agency ladder. I've had longer holidays, more days off, seen more school plays and played more park football. Which is not to say I've worked less - I suspect I've actually worked more, but I've been able to decide when to do it and I've wasted much less time.
I know that status meetings are crucial for large organisations, but it's nice, every now and then, not to be in them. On the other hand, I've been slightly terrified for five years, never entirely comfortable and secure.
Every game of beach cricket has been ever so slightly marred by the nagging thought that I'm not earning any money by knocking a cover drive over the sandcastles.
And even when you are earning, that fear of where the next job is coming from never leaves. If you're a worrier, it may not be the job for you. Similarly, if you enjoy the satisfaction of being in a close-knit team and a completed project, you should probably think twice about joining the freelance life.
The team that calls you at midnight begging you to help with a pitch will cheerfully deny your existence when you're chasing them for payment. Freedom for you equals disposability for them. You're out as soon as you're done. It's fair enough, but sometimes you miss the narrative arc of a project begun and completed together.
And, and ... oh, blimey, I'm out of words. More on this next week.