I as taught metric but real life used imperial, so I was mostly confused. I prefer metric though as it's less confusing and, IMO, the lauded "You can divide by lots of different numbers" is mostly unnecassary as rounding off to the nearest mm, 5g or 5ml is accurate enough for almost all everyday waork.
Growing up in the U.S. in the mid-20th century I was raised, even immersed in the imperial units (more precisely "U.S. customary units") system. We were, of course, made aware of the metric system and to a large degree it was used in sundry science courses (I was exposed to more of that perhaps, since I always pursued a fascination with science), but everyday life was all imperial.
Then I got into construction. I began working as a reinforcing steel ironworker (a "rodbuster" in common parlance). Rebar is labelled in increments based on the diameter in eights of an inch. No problem. Until a company I worked for picked up some projects in the Caribbean. This is when I not only had to use drawings and do layout using metric, but also learned about metric rebar. Much bigger hill to climb. Not merely a change in the labeling system, but a change in the actual diameter of the bars. This was more disturbing. The differences were minor, but when you have worked with and become familiar with handling a product over years they were noticeable. The bars
felt different. I wasn't really there long enough to get used to it.
Later in my career I did a lot of layout work and eventually drifted into what is known in the trade as a "field engineer" (no jokes please). This is the guy you see standing behind various instruments on tripods. It is almost all measuring. From stake out to layout to marking and measuring elevations.
Construction site documents (as opposed to architectural, engineering, and shop drawings) tend to use whatever system the site architects and engineers prefer, and decimal feet is quite common. Common enough that over time I didn't need to convert the decimal part of the foot in my head. I just worked in it and inches simultaneously. Kind of like being fluent in two languages.
Angular measurement could be DMS, decimal degrees, or even, very rarely, radians.
It's all what you are exposed to and have time to get used to.
Frankly I wish that the U.S. would push the use of metric more adamantly. It has at least technically been the system accepted as the standard for the U.S. since 1893 and again in 1959. But we are a stubborn and recalcitrant people.
I wanna stick with Fahrenheit, though. It just feels more appropriate. So sue me.
