Take two IMAO fans. They are right-wing, hate commies, etc
One is a former socialist, the other was raised right-wing. Who understands socialism better? Probably the former socialist. He's also more likly to have commie sympathies, but that's another issue.
The point is being a former-X generally means having a pretty good understanding of X. Because actually being X usually means understanding it well.
Now, imagine someone who was a former everything. Every important tradition, he's either a former or current member.