What the conditions are, what the wildlife are doing, and all the "old sayings" won't predict your fishing success !! Remember - you gotta find'em before you can catch'em !! Knowing where they are (or should be, given the current trend of conditions) comes from knowledge about the habits & habitats of the fish you're after. And, even that may not always work in your favor, since the fish have a habit of doing things that defy all sense of reason, at times.
And, you sure won't catch'em if'n ya don't go !!

... pappy