I have had the excellent good fortune have worked on an XP team with an excellent and enthusiastic leader. Under him I learned the basics of test first programming, the benefits of pair programming, use of mock objects and the difference between unit tests and functional tests. That was in 2003

Since 2003 I have worked on some projects where, some of the time, we had sufficient resources to work within some of the agile or XP disciplines, for example test first programming, and pair programming.

My experience with unit testing is moderate at best, I can and have done it but so much of my past few years has been spent in emergency delivery mode that a more rigorous approach to test first programming has not been applied. I am not counting here using JUnit for extended broad functional tests, I've done that pretty heavily, but that isn't true unit testing, which can be done without the network cable even being plugged in.