You sound just like me before I started teaching.
It was a humbling experience the first time I actually found myself in charge of an actual course, and realized that there is quite a bit more than “few little things here and there”.
I remember thinking “gee, I thought I had it all figured out, and look how much more complicated it is than I thought… and how little I really understood about it … and I even had the nerve to lecture about it people who had done it for twenty years …”

Why would they lecture it if they would not want you to learn it?

Actually no, I have not passed that kind of judgment. My argument is based on the observation that students more and more expect to have access to things which until ten years ago (yes, I was teaching already back then, and internet existed ) they did not seem to need. I do not claim to understand their motivations.

It is also based on the observation that in the course of a single term exceedingly few students come to my office in the first place, and when they do they never ask how a particular formula was derived, or to rehash a specific concept or even show how the algebra was worked out. The just want to know how to solve what the answer is to a certain problem.

Detailed notes are like the solution manual to a set of problems.

… which is usually not handed out to students, the premise being that they really should try and work them out by themselves. Sure, it would be easier, faster and more efficient if you could just look up the solution, instead of “wasting” afternoons trying to obtain it on your own, but most of us think that that would defeat the purpose of assigning homework in the first place. Same goes for online notes.

Wouldn’t it be beneficial for the student to see the problem work out differently by someone else, i.e., you?

Sure, and that is what lectures and office hours are for.
The time “wasted” in trying to figure out how to go from that starting point to that final formula is regarded by many of us as an essential part of learning.
If we accept that premise, debatable as it might be, then there is no escaping the fact that there exists a line beyond which one is spoon feeding students, taking away any kind of intellectual challenge and rendering course work an altogether less fruitful experience.

Although I agree with you that a good grasp of the subject matter must come with practice and independent reflection, I don’t believe posting detailed notes online will discourage students from these activites.

Your entire argument is based on the presupposition that students are lazy and apathetic, and if detailed solutions are available to them, all they’re going to do is simply read the answers and memorize the steps.

The point I’d like to make is that there’s no remedy for laziness and apathy, whether it’s for learning, voting, or something else. However, having detailed notes online provides many benefits for students than simply offer itself as the easy way to learn. Detailed notes are like the solution manual to a set of problems. They may offer students with a method to a problem that they either haven’t thought of or simply forgotten. Of course, to use these notes most effectively, students should first try to derive them on their own. Like having an alternative interpretation, worked out solutions are like an alternative method. This is why you post detailed,worked out answers for home work problems. So why not online notes?

In addition, having notes online will make studying more efficient for the student. It takes longer to go to your office than checking online notes. Often times, when the student gets stuck all they need is a pointer from the notes. As a result, they’ll only go to your office if they have more serious questions.

Lastly, the techniques are most useful and are tested on the exams will often come from the notes than from the text book. In fact, text books don’t intend to teach techniques and methods to solve a problem. Instead, they rephrase the fundamental concepts I hear from you in the lectures. ( I guess this point can be argued depending on the textbook used, but many advanced text books don’t bother with the details of algebra).

So where can students learn the algebraic methods and techniques to solve a physics problem? You’d say, well it must come from practicing “on their own”. However, is it reasonable to expect students to come up with everything on their own? Wouldn’t it be beneficial for the student to see the problem work out differently by someone else, i.e., you?