I don't know if im just different, or lucky, but I started my A-levels after gcse's, my life took a nose dive and I pulled out int he 2nd year.
I had to do something so I went to one of those training agencies that pay you £45 a week to learn an NVQ (far from ideal, I do not reccomend it), well I finished my NVQ lvl2 and I was waiting for a placement for a lvl3, the IT guy left so they gave me his job as a placement, 4 weeks later I was their technical manager for their training business and web design company (I was 18), I never did get that nvq lvl3 tho, 3 months later I was bored and wanted more money, so I got a job in a call centre for a well known telecoms company for they internet support, and I loved it, got promoted to web designer, then got laid off, went to the other big telecoms company, stayed for 2 years, then went back to the first, and this time round I hated it, I guess I had matured a bit and suddenly found myself expecting more from a job.
Due to my lack of qualifications I really struggled to get an IT job, I did telebanking, delivery driving, but just could not get an IT job, I started my own business, sold it after a year, had two years off due to ill health, then all of a sudden I get a phone call for a deployment engineer job for 3 days work, I accept, and I am still contracting for the company 2 years later, on twice as much money as I have ever been on before, and im now in charge of mobile devices, sap and build development.
But im worried, the second this contract ends im in the same position again, of not being able to get a job due to qualifications. I am however studying for my ccna.
The moral of this story, is that you can get by without qualifications, but luck has a big part to play in it, if you don't want to rely on luck the rest of your life, then do it properly now, If I were you I would go to uni, get a degree and then maybe a ccna or something (skip the MS ones) while working in your first job (probably a support role).
Once youve got a degree and some decent certification you have a very good base to work on, as soon as you get a semi decent job, stay there a few years and build up experience, try to get experience in different os's, networking etc, and you can be set for life
DJH