Computer fundamentals haven't changed in the last 15 years. A laptop isn't going to teach you anything that your parent's 8 year old desktop won't, especially not an EEE, which bears little to no resemblance to the vast majority of computer hardware in the world.

So yeah, go buy a laptop or an EEE for a toy if you want to, but your parents are right. If you can't afford to pay rent, you probably shouldn't be buying a laptop. If you want a new computer that is going to teach you A++-type stuff, build a cheap desktop with parts from newegg. If you want a good companion to your n800 for work and travel, I recommend a budget laptop.