I did. Both in undergrad and grad school. Actually built 1:1 assembly models with real materials (wood, masonry, steel & welding). My grad school detail course was taught by one of the authors of the building science website. 

I don't recall doing many details in school.  Design and theory live comfortably within the walls of academia, while construction does not.  It wasn't until I got out of school and onto a jobsite that I started to understand tectonics and details.  Until you've stood there and stared at a connection detail or looked at how materials actually come together, it's difficult to speculate.  

You have the right idea on reviewing good books.  Those will be a good substitute until your internship.

No. Some people tried to but it was clear they were just copying something they found in a book or online and didn't really understand the detail and how it related to their project, thus it was generally frowned upon. Looking at details, yes. Creating them or pretending to, no. 

In our various materials and systems courses throughout my undergrad and grad programs we did 1:1 detail models - both of details of existing well-known buildings and mock-ups of our own designs, and quite a lot of drawing and digital modeling of details, both existing and of our own designs.  I would say that it wasn't particularly well tied into our studio projects.  Usually we were encouraged to present details as part of our overall studio project presentations, but there wasn't a lot of focus on them, or great rigor in critiquing them.  Also some of what we learned and mocked up were interesting historic techniques but with minimal present-day applicability for most architects (examples: slate roofs; cork wall insulation...)

I learned much more from working "in the real world", by figuring things out from firms' past examples, and working out the feasibility of my designs with our contractors, consultants, product reps, etc.

yes, in a 5 year B.arch (US)

it wasn't a single class but part of the overall curriculum during years 2+3 to develop key details for our studio projects as part of understanding the process. To some extent it was self-studied since the relevant details depend on the particular design.  these were presented as part of the project through both models and drawings.

It didn't feel comprehensive, but ultimately good detailing depends on understanding the process and knowing what principles apply so that you can look for the information you need to complete the detail.

It was a revelation to start working and discover that the hard things like curtain wall details are developed over a period of months with input from possibly a dozen specialists - you as the architect don't always need to know everything, just how to analyze a condition and set an appropriate design direction.

Agree with others, looking at construction and understanding what actually needs to be detailed to explain a design is key. Otherwise you end up with idiocy like someone here who described detailing the section of a marker board frame. A lot of the most complicated details are a matter of integrating several separate systems and understanding the requirements of installation that manufactures describe and how that fits into a construction process.

Try to spend some time observing construction up close and it will make sense very quickly.

None, as most of the teachers had little to zero such experience.

Yes, of course - all of our teachers were practicing architects, so we had to deal with planning, zoning, programming, structural design, mechanical systems, energy calcs, detailing, permitting and contracts. One of my "internships" which are called "practice" was to re-build a church in a poor neighborhood that had been burned by the dictatorship, the other practice was in a building dept. in a poor municipality helping people regularize their self built homes. All of it in 10 semesters.

I was taught the detailing in my B.Arch degree during year 3 of a 5 year program. 

yes and no ... mostly no. 

We had to produce details for some studios, but it was more or less an exercise in copying out of magazines and trying to figure out what was going on. No one really cared if it worked as long as it looked good on the presentation board. Once that was figured out, the effort put into learning the detailing was minimal at best. Even in the design-build studio I took ... there were only a handful of us working out details. Everyone else was tasked with other things. Those of us that were tasked with working out the details had either office experience or construction experience. 

I mostly learned from building things, working closely with good mentors, and figuring things out from knowledgeable product reps and consultants/subcontractors. 

Thank you all for your input. 

There is no doubt that detailing is a very important skill for an architect. 

At the university I am attending I have discussed this issue with several of the students and there is a large majority who would be very interested in attending a detailing course. However, the curriculum does not include this, although there is strong focus on technical courses like structures, facade design, services etc. 

In your opinion, what is the reason why this skill is not entirely taught at school? 

every time I read the thread title it reads, did you get caught detailing in school, and I always say yes, no matter how much I tried to stop.