TITLE: What are the suggested prerequisites for topology?
QUESTION [11 upvotes]: I am interested in topology but I don't know if I can learn it without learning something else first.
I've done:
Algebra 1 and 2
Euclidean Geometry
Calculus
Is that enough if not please tell me what else I need to learn.

REPLY [8 votes]: You should know basic operations in set theory.
For example, do you think that:
$f(A\cup B)=f(A)\cup f(B)\: ? \:   f(A\cap B)=f(A)\cap f(B)\: ? \:f(f^{-1}(S))=S\:? \: f^{-1}(f(T))=T \:?$  
...and can you state a precise context in which these questions make sense?