I also started with the TI-99/4A, I was in 7th grade at the time though. Lots of memories writing BASIC on that. I don't envy you reprogramming the ASCII characters for Greek, I remember I had tried to make real lowwer case letters instead of just small capitals amongst other things, and had the Hex to bits conversions memorized.

The software though that got me interested more in the database side of things was in my first real job when I started using FoxPro for DOS. Yes I had database classes in college that worked with Sybase but those didn't quite grab my imagination the way FoxPro did because we didn't build any front end for the database in college. FoxPro allowed access to the data by SQL or by lowwer level commands. I learned alot about databases from utilizing both, including my preferred way of "pivoting" data using the IIF() function of FoxPro in a SQL query, which I translated to DECODE() function when I learned Oracle, which I translated to CASE in SQL Server.