The pathfinder rules say:
A creature that successfully saves against a spell that has no obvious physical effects feels a hostile force or a tingle, but cannot deduce the exact nature of the attack. Likewise, if a creature’s saving throw succeeds against a targeted spell, you sense that the spell has failed. You do not sense when creatures succeed on saves against effect and area spells.
If a creature's saving throw fails against a spell, does the creature still feel that "hostile force or a tingle" or otherwise know that they've failed a save?
(I'm asking this question because it's relevant to How powerful can a 20th-level Wizard make a 1st-level Fighter without allowing him to realize it is the Wizard's doing?)