not even in geometry?
I figure the reason that some Junior College classes are less rigorous is because those classes have to cater to the majority of students that enroll. As I am sure your aware, a large number of those students aren't to advanced or don't care to learn the theory behind math. This is not a put down to JC students, in fact there are many bright students who go to JC's for many reasons ( $$ ) other than brains (or a lack thereof ), who then transfer to prominent universities.
Unfortunately most intro calc classes (1,2,3) focus more on the calculational side of calculus rather than theory. This is true even in most universities, the exceptions are the honours courses. However, your prof should at least go over some of the proofs in class, but usually won't actually ask you to provide a proof to a theorem. If you eventually take Linear Algebra, then you should be exposed to proofs and will be asked to find proofs yourself, no matter where you take it. For the majority of students, this seems to be the natural course of things.
Here are some suggestions to help you prepare for the future. When reading your book, read carefully and make sure you understand every derivation and theorem. Some JC's offer courses that give an intro to logic and proofs. One course I know of called Discrete Structures (or something of that nature ) allows you to sample set theory, logic, combinatorics, probability, graph theory, etc... all in one semester. A course like that is useful for almost any math class, and can also provide a good foundation.
There are also resources available to you outside of your school ( too many to list ). Try getting ahold of a copy of some of the more advance texts on calculus such as Spivak, Apostol, or Courant. There is also a whole bunch of goodies available to you at the "open-coursware" section of the MIT website:
http://ocw.mit.edu/OcwWeb/Mathematics/index.htm
There you can find entire courses on video ( such as Lin Algebra and DE ), Professors lecture notes, etc..
And of course, there are the archives here at PF! You'll find a world of knowledge here, and better yet, tons of people with an impressive breadth of knowledge who are more than happy to provide guidance as well as assist you with your homework (for FREE!).
Another thought, most students that go on to upper devision math are the ones that don't just rely on what's taught in their classes. They're the ones that go out and learn for themselves, and when they don't understand a concept, they refer to another text on the subject. They start reading the textbook before any class begins. So IMO, even those students that just learn the "tools" from their classes are still behind.
Good luck,
-MS