I wonder if it is something to do with puppet. I've never used it (I wrote my own thingy before puppet existed), but I gather puppet comes with a whole pile of

I wonder if it is something to do with puppet. I've never used it (I wrote my own thingy before puppet existed), but I gather puppet comes with a whole pile of configuration thingies out of the box. For example, maybe you don't have to know how edit the sudoer's file to prevent password prompting because puppet has a puppet way of doing it that edits the config file for you. I could well imagine if you did things by editing puppet files for a few years you might forget the underlying config file syntax, or even what config file ends up being edited. If that's true he'll pick it up soon enough. The muscle memory will start flowing again. If he wants something to panic over try moving to k8s. If effectively includes a puppet like thingy done a completely different way, and worse it builds a very different computing model. Use that for 10 years, then try to re-adjust your thinking back to a single server model that you maintain by editing config files and you will be in for a rough ride.