Window for editing your post

Not a topic on DP.  Will ask here anyway.

I wanted to edit a post that I made a couple of hours back but did not find the edit/modify link anywhere.  Found such a link for a post made a few minutes back.   Is the window for editing your own post so small?

I mean, sure if so many people have replied and you edit the original post to be completely something else, it will not make sense.  But corrections, meaningful edits should be possible for someone reading from the beginning.