So my story:
Back in 1994 I was 16 years old and failing in school. My dad came home one day and told me that I needed a hobby and that I was going to get my ham radio license. I had no idea what a "ham radio license" was, but sure, whatever, what the fuck.
Fast forward one year and I got my technician license in the mail and started talking on the radio. From there I became interested in electronics. I was never interested in computers, but I wanted to be an electronics engineer.
Fast forward 2 years and I was working as an electronics tech in a guy's garage doing product safety testing and RF compliance testing (those nice UL and CE marks you see on all of your computer gear). I loved my job, because honestly, who doesn't love to blow shit up for money. So, in order to actually do my job, I needed a computer. Of course the guy I worked for didn't have computers in his lab, but merely computer parts. So, from there I had to build all of the computers myself from parts up to installing DOS 6.2 and windows 3.1 on them. Wow, that was pretty fun/cool. I even got pretty good at DOS.
The next year (1998) I told my dad I wanted to learn Unix. I had heard of Unix because a friend's mother worked on Unix at the phone company and it sounded cool. So for Christmas, he bought me a copy of Red Hat Linux 5.2 and several books to go with it. I installed it on my computer up to getting X Windows working. Luckily, all of my hardware was supported and even RH 5.2 was pretty decent at figuring out your hardware.
This is where the fun stopped. It turned out that Linux was a frustrating pain in the ass. I banged my head against it for 6 months and even contemplated giving it up entirely except for two things that happened. One, I took some Unix classes at college that put everything together for me. Two, I figured out how to install KDE. KDE made the desktop easy enough to use that it got out of my way to where I could start to focus on the more fun stuff.
It took 2 more years of pain and learning before I got a job as an electronics tech at a small business. When the guy saw that I knew computers, he basically made me the System Admin as well. All for a cool $14.50 per hour. That network was Windows NT 4.0 and not Linux. So I actually got pretty good at NT 4. The lucky break happened when our Sonicwall firewall burned up and I replaced it with Linux and iptables. I also figured out how PPTP worked, so I made the company a VPN. 3 years later, after learning a ton, I got laid off from that job and had to find a new one.
More pain commenced because it was the pit of the dot com crash. There were no junior Linux jobs at all. However, I managed to land a contracting job where I helped the other Linux admin implement a bridging firewall / IDS based on snort and ACID. It helped at that point to find out that I actually knew more than the guy I was helping.
After my contract ended, I was unemployed for 2 more months before I landed a contract job for a NOC at a large Internet meeting company. That job was hell on earth, but it taught me how to be cool under pressure to the point that no pressure since even phases me. I can deal with any situation, because once you have a VP of operations screaming to "GET EVERYTHING THE FUCK WORKING RIGHT THE FUCK NOW" at you on the phone in front of 200 of your coworkers you learn that nothing really is that bad.
From there I quit after 6 months of hell and went to work for a University as the Senior Systems Admin for a small Astrophysics center and it's basically been all uphill from there. From there I worked at a MSSP as their in house System Admin and then at my current job where I'm basically the most senior Sys Admin for a small company that supports medical research.
It's been quite a ride and while it hasn't always been plesant, I've learned a lot and worked with some really cool people.
My career advice? Take your breaks where you can get them. Be persistant. If you give up easily, you'll never make it in this field. Learn to function under pressure. Learn how not to be a condescending asshole to the non technical people around you, because you WILL need them eventually. Learn to work with people rather than always saying no. Learn the business you work in, this will help you to understand why people sometimes ask you to do things you think are stupid. Lastly, don't spend all of your time at the computer. Get out in the world now and then.