[Retric]

isn't something your roommate could teach you which would be good and I gave the examples

In many ways two specialists in the same area can teach each other far more things than two specialists in different areas. The problem is until you know a lot learning from a wiki is often the best approach, however the more you know about say java script the more things you can learn with that foundation.

Think of it this way, how long would you need to spend with tiger woods before he becomes significantly more useful than the average golf instructor. And how does that change as you go from a beginner to the pro level.