The biggest problem with this blog post is its assumption that there are "shields" to begin with.
Whatever I'm doing there's always a possibility of something better out there. Rather than throw up "shields" and shut off all possibility of serendipity, I just evaluate opportunities vs what I'm doing now (and factor in some switching cost). Obviously if I'm heavily invested in a long-term track, it would have to be something amazing to make me leave. But why would someone set up mental defenses against even the possibility of something amazing?
Supposedly I get a call from the POTUS asking me to be a part of the USA digital service with a mandate to dismantle (or to come up with a plan to dismantle) the NSA surveillance system, I would say yes in a heartbeat, no matter how good my current job is, or how attached I am to my coworkers or working environment.
There's no such thing as "shields" I agree with you totally.
Whatever I'm doing there's always a possibility of something better out there. Rather than throw up "shields" and shut off all possibility of serendipity, I just evaluate opportunities vs what I'm doing now (and factor in some switching cost). Obviously if I'm heavily invested in a long-term track, it would have to be something amazing to make me leave. But why would someone set up mental defenses against even the possibility of something amazing?