I used to be a Sys Admin and fell into administering SQL Server at the same time, I'd only worked for smaller businesses at the time. Because the network wasn't very large I had time on my hands so I spent time learning VB.NET, the development language used by the company, to work on small projects that wouldn't interfere with my Sys Admin tasks. They also saw fit to send me on a few SQL courses, one of which being SQL performance tuning ran by Itzik Ben-Gan, after which I performance tuned the system.
Shortly after that I was made redundant which gave me three choices of career, stick as a Sys Admin or try my hand at being a coder or DBA. I didn't want to stay as a Sys Admin as I was bored and found the other two far more interesting. Coding and DBA work seemed to pay about the same, but there appeared to be less DBA's out there, the decicion was made. I took a chance and went for a contract DBA role covering maternity leave.
I honestly haven't looked back, the job fits and seems well matched to my personality type. My whole way of being is about efficiency (I'm not saying it's the best way to be, it's just the way I am). For instance, I know to the minute how long it takes me to get ready in the morning or when cooking, everything is prepped before starting to ensure the work area is tidy so I can cook without distraction. Enough babbling....
I'm now a Senior Database Dev and have just recruited my first member of staff for the newly formed database team. I think I made the right career choice :-D