Of course you're thinking about it, Megumin! Ever since you went out into the wide world, you've been growing as a person! Only mentally, though. Not physically. Never physically.

And since only a complete weirdo like Darkness would willingly be your friend, obviously part of your (non-physical) growth is learning how to be a good friend that thinks of her happiness.

"Still, that you'd even try...I'm so glad we're friends, Megumin!"