While I'm not an engineer, the solution to your quandary seem simple to me. If you are concerned about a lack of projects & deadlines - create some.
My first couple of years in retirement were quickly consumed with household projects/renovations. Not being overly "handy," I enjoyed learning the BASICS of tiling, plumbing and construction. I imagine an "engineer" (depending on the type) might also enjoy this type of activity.
My current project is the restoration of a car that I've wanted since childhood... a "series" land rover. An ideal "engineer's" car, these old vehicles are essentially big erector-sets. They are simply (but ruggedly) constructed and made to be field stripped in the jungle with just a wrench & screwdriver. They are fairly inexpensive, have a well stocked parts supply and (like the FIRE group) enjoy a friendly community of 'blokes' anxious to help with advice and support. As a benefit... if you enjoy "slow travel," there are few things on the road slower
Whatever you choose as a "project" simply enjoy the freedom of choosing your own