Oh, you know, that’s a good question. I didn’t take it that way but I guess it is kind of hazy, let me work out how I immediately took it and moved on.
Let’s see, if you remember the conversation in ep 7 when Sterling and Blair were on the stakeout with Bowser he implied Michelle could have changed and things could work out this time and Sterling latches onto that and is like, does he really think people can change, in the context of April. And then of course after that, for a brief few days it feels like everything has changed and is so perfect. So when Luke says, if you gave her a chance, you’d be surprised, people change, I think to Sterling, it reminded her of how she had actually experienced all that, but now it was all over. To me it was about the situation changing back, that April had “changed” back into how she was before, too afraid to even be in a relationship.
And also, since Sterling’s next line was about missing Luke and then kissing him, you could almost see her trying to will herself to change back into the person who was happy with him. Ultimately, I read it as a lament that she’d gone on this whole journey and things were back to her and April not being together and was all that change, forward and then back, worth the hurt.