I started getting interested in electronics right about that age. Started Designing and building HiFi amp kits, and speaker systems. Also made a few robots (using raw electronics, not lego mindstorms). Back then Lego was still very expensive and I couldn't afford modding lego parts to fit electromotors or sensors. Mindstorms was non-existent, so I drifted off into electronic. Studied it at uni, and soon Lego was forgotten...
20 years later, I can afford Lego again. I am also not shy about cutting, modding and gluing lego parts to make more complex systems, robots, fit them with electronics, etc. etc. If you have an engineer's mind and love to create new things, grab an Arduino, a motor shield, a few electromotors or stepper motors and build your own complex mechanisms. That will transition you smoothly into your studies, uni, etc. If you are more creative and artistic, start using lego to express yourself creatively - build sculptures, etc. You will find that lego, especially with some ABS glue and hot-knife can be a very malleable medium >:)
Best Luck,
Jack