So, I've been thinking about certain characters in my story a lot lately. In my erotica about Apollo, one of the main characters seems to always pull my attention even when I'm not writing her. My best friend has read a couple-few chapters of the story, and even sometimes she mentions her!
Her name is Makoto. She's the best sassy character I'm pretty sure I've ever written, and she just makes me smile and laugh. I wrote the things she says and they still get me going. Some days I'll randomly think of scenarios with her, or her back story, and then I'm just like... Damn, I miss her. I got massively stuck on the story with her in it and haven't touched it in... over a year, maybe two. I may just write a short with her as the MC and see how that gets my creative juices flowing... or if it just inspires a whole other thing with her, haha.
Another of my characters that seems to always stick in my mind is Johannes from my novel I'm currently querying. It's sort of a shock to me because in my first draft of the story, he was 100% the villain. (Which has changed immensely since then, but he's still a dick, lol.) I didn't care for him, he sort of irritated me, and he was rude. But as things changed, he started clawing into my brain... I've had... three dreams of him now. Even the editor that worked on ELA said they had a dream of him! He's a worm that will get right into your brain, LOL. He'll make you love him even if you're mind is telling you not to.
There's a couple other characters that always pop in my mind (Henry from my EotG series for sure.) and it makes me feel good as a writer that I can manage to do that... And I hope when others get to read these stories that my characters stick with them too.