Despite changes in life, some things maintain a level of continuity. They are things that one can always depend on to remain the same. Eaach person needs to identify such things in their lives and determine how they can benefit from these things.
A single positive (or negative) childhood memory of a small item or situation can have serious and huge effects on how someone will react or treat that item or situation.
The routine of your family sitting together by a big window and watching the lightning during thunderstorms will create a different emotional response in your adult self than the routine of hiding in individual rooms, bedrooms or the basement, and trying to shelter yourself from the thunder. One with warm family memories will enjoy the sight and sound of the storm. Where one with solitary, fearful memories will feel anxious and panic and try to hide. Both are unique reactions to a consistent occurence.
There will always be thunderstorms in life, be they literal or emotional. Each persons reaction will be different. Don't think of why someone is different than you, think instead of what lead you to your own reaction, and what may have led them to theirs.
Seek to understand, only then can you accept. Trying to change the way someone feels rarely, if ever, ends successfully. If you try to understand the reasoning behind your own reactions, and theirs, instead, cooperation is more easily accomplished. Then a middle ground can be found, if necessary.