Originally Posted by ~Tenderness~
As for her being ditzy she was one of the most intelligent characters in the game, it was she who figured out a way to rescue Tifa from Don Corneo's, it was she who figured out what Sephiroth's plans were in the temple of the ancients and it was she who figured out what she had to do in order to do her part to help the planet. Also just because Aerith sometimes had an optimistic friendly exuberant personality doesn't mean that she wasn't street smart. Also such personality traits do not mean she was completely innocent. She was street smart enough to know what Don Corneo's places were, enough to bargain with traders such as the time she bargained with and convinced a man in Wall Market to make a dress for Cloud and enough to receive good money for her flowers in Wall Market. She's referred to in the game as a good business woman and her business talent is again commented on in Itadaki Street Special, I heard that Tifa a fellow business woman says that Aerith has a knack for making profits :)
She was also very brave at times such as the time she gave herself up to protect Marlene and when she followed her destiny by praying for Holy.
I kind of find it sad that if you're kind, friendly or optimistic as Aerith was or indeed as I am and others that I know are you get thought of as stupid :(