[p4] Using previous version of a file

[Prashant Deva]

Ok, I really dont get this about perforce.

Say i am working on revision 5 of a file.
Now, for some reason i dont like these changes and i want to go back to rev
2.
So i check out rev 2.

But now when i try to check in my file, it wont let me do so until i get the
latest version.

I thought the whole concept of using a version control system is so that i
can use previous versions of a file.
So why does perforce insist on me getting the latest version till i can
check in?

Prashant