Well, the young kids wouldn't have known him as long, and he does have the birthday as an excuse for the change. The older girl seems to just be happy about the change without caring much about why, and the other 2 still seem suspicious.As much as I enjoy this type of story, I always find it strange how everyone isn't freaked out about his sudden complete 180 in behavior.
Based on the flashbacks of how he found them all (so far), it seems to me like he may have cared at least a little at first. It's possible that being constantly drunk and addicted to gambling made him worse (as it tends to bring out the worst in people), so perhaps he was nicer before? 🤔