My so-called career has been revolving on the telecoms world since 1995. I'm currently on my 4th job, jumping from vendor to operator to vendor and now to operator. For the past 10 years I can conclude that the telecoms world is very small that the chances of working again with an ex-colleague is very high. I've made the table below to stress my point:
The table summarizes some of my ex-colleagues and the companies that they've worked for and are currently working in. As an example, Guy 1 (obviously me) is reunited with Guys 16-19 in Operator M (they met previously in Operator G). Side note: there must be something wrong with Vendor A and Operator G since all the guys listed from there have left for another company. Hmmm....veeeewy inteh-westing.
It's nice to know that all my ex-colleagues from the different companies will eventually meet each other when they move to different companies since, as I said, the number of telecom companies are limited. Of course we also have to assume that they don't change their field of expertise (from telecoms to nuclear physics, for example, but that's a long shot).
Moral lesson? Never burn bridges. One way or another, the [telecom] world will conspire for you to meet again.
It's a small world after all...It's a small world after all...It's a small world after all...It's a small...small... world.