I bought a pi out of curiosity (and because they are cheap). I loved the diy aspect, and learnt about connecting other things to it. This led me to the arduino, and from there to basic electronics.
If someone five years ago told me that I'd have designed and made a tracking unit for my car, that you can send a text message to, and it replies with the co-ordinates of it's location I would have laughed. It cost me less than twenty quid to make. I'm now planning to learn how to write an android program for my phone that sends the text then pumps the result into google earth.
Get a pi. It may end up gathering dust; It could inspire you. It costs thirty five quid.