My son started sleeping through the night just before he turned 2. We did not sleep train. He still wakes up every now and then, just needed a tuck in and to know we're there. Think about it, even adults wake at night and struggled to fall back asleep. They're little. They need help learning to fall back to sleep. It takes time. I don't loose sleep waking to tuck him in if I need to. I also think with time you just adjust to the new sleep schedule 🤣