It would seem that the translation of this sentence is heavily dependent on the context in which it is uttered, a context here unrevealed. So it might mean: “So glad you realised.” Or: “Phew! I noticed!” Or, as suggested: “Oh, what a good idea it was of yours to regain consciousness!”
@Terence
Great explanation! Let me add some notes.
So glad you realised.
Phew! I noticed!
Oh, what a good idea it was of yours to regain consciousness!
The first and second interpretations can be rephrased by 気づいてよかった (i.e. drop が and replace つ with づ for phonetic liaison.) There is no significant difference between 気がついて and 気づいて in these contexts.
But we don’t usually say 気づいてよかった in the third context (though it might be understandable.)