Life teaches you!!
But looks like Meera herself is not using the teachings of life. She is still allowing MS to walk into her house anytime with full haq as if he lives there. Bas chai poochne ki der hai. And she stands meekly listening to him also. Plus answers his questions when he asks for info.
When she shd be throwing him out the moment he appears at their door, refusing to give him a moment of her attention and telling him it is none of his business if he asks something.
Yup, as per precap, he was again allowed inside the house, to get the opportunity to negatively influence Ishaan,