4 years later

So my first bf emailed me 2 days ago as I’ve had him blocked on every social media platform since we broke up 4 years ago. I’m not naive, I don’t fall for that ‘I’ve changed’ bullshit nor do I ever require closure but and he’s not tell me he has changed but from what I’ve seen in the last 48 hours (through our conversations) I’ve definitely noticed a change, it’s like I’m talking to a new person. He’s compassionate and remorseful for how he treated me back then but he’s not the closure or apologies down my throat, it feels genuine. I don’t plan on getting back with him, ever, but I’m just curious, do people really change? Have you been in this situation, how did it pan out?