Quote Originally Posted by chaika
так и не + verb = never
Искал, искал, так и не нашел.
So following this, так и + positive pf. verb = always.
But even so I always knew that a dream wasn't enough for love.
Hmm... I think "так и не" has no positive modification.

1) IMO "так и знала" is a specific phrase for verb знать (and it is impf).

2) There is a phrase "так и + pf or impf" and it can have different meanings.
a) = in the way described before (not really a phrase, it is a normal usage of так with intensive и = just)
Так и случилось. = It happened right in that way (as predicted).
Хорошо, я так и сделаю. = OK, I'll do (exactly) as you say.
Обычно так и бывает. Usually it happens just in that way.
Попал в аварию? Так ему и надо! He got into accident? He just deserve it!

b) describes the following action as very emotional
Увидев Ленина, старик так и сел. = The old man just sat down where he was when he saw Lenin. (beacuse of being struck by surprise)
Так и хочется оторвать ему голову! I want so much to tear off his head!
Phrase "так и знала" is from this series but not exactly.