I've only been a professional, paid developer for 4 and a bit years, but I've spent a lot of time wanting more time to do my own thing.
For my first year and a half I worked for one organisation. It was a good place to start. I had a great many experiences, including negotiating a (relatively) large increase in my salary, and moving across the country when the business migrated.
After 1.5 years in that job I got a call from a manager (I'll call him G) who had quit to go freelance, and wanted me along on his latest contract. The money was double what I was getting, and I was bored and frustrated in my current position (for many reason, mostly bureaucratic), so I took him up on his offer.
I set my self up as self employed, and started on the gravy train. At first I found things to be great. It was a contract at a company that was only 1 year old, so we had a lot of leeway, plus it was the same sort of company I had been working for before (and a lot of the same people, but that's another story), and I could work from home. This was important because the site of the contract was an hour and half away, and I didn't fancy a 3 hour round trip each day.
Unfortunately, after a few months, things started to go down hill. I had moved house again by this point, and I was closer to the customer site. Interaction between us (by us I mean the group of people that G had hired) and a couple of third parties that the customer was using were strained, and development was slipping. The customer was getting shirty with us (and everyone else) because they wanted to launch and their systems weren't up to scratch. I had to start coming in everyday - a 2 hour round trip. Requirements for our projects were spiralling out of control, and I was incredibly stressed. G had fired one contractor over a disagreement, and our morale was low.
After a few more months of this things levelled out, the customer got enough of what they wanted to launch on time. Things still weren't up to scratch, but work was steady instead of out of control.
At this point I was left doing something I found incredibly dull and boring. I carried on because I felt like I should finish what I started, also G was promising me more interesting work further down the line. I was still having to go on site everyday and this was having a negative impact on my home life.
Things didn't change in the sort term (a few months), so at 11 months of being self employed I told G that I was going to move on in 2 months, and try my hand at my own thing. I spent those months tying up loose ends and producing a lot of documentation.
I left, but a month later I was brought back in because G hadn't had time to find someone to replace me, and I'm not one to let people down. I carried on for 6 more months, after which I was replaced (thanks in no small part to my documentation).
I had earned a fair bit of money (possibly more than fair) so I set about working on my own project. This was going well, although it didn't pay anything. Due to my lack of income, my then partner (as in romance, not business) started to complain that I wasn't doing anything. She couldn't understand how I could work on something that (probably) wouldn't make me any money.
I promised her that I would find a job after 3 months working on this. So after I put my project into late alpha/early beta (where it's been for some time now, without real development), I stopped being self employed and got my self a salaried job.
I have been in this job for 4 months now, and I feel more free and happy than when I was freelance, even though I've gone back to the same salary I was on before I was freelance.
My hours are better, the commute is shorter, support from my manager and team is better. My work day is far more pleasant than it was in the 3.5 years before
I understand the desire to be more in control of your work day, but freelance doesn't always give you that, and it can make things worse, not only in your work life, but in your personal life.