It is the old memory that belong to us.
old用进去好怀旧吧,哈哈。- -
This is our own memory, that belongs to us.
What a great memory we have, that only belongs to us!
This belongs to memories that we share together.
这是我能想到最怀旧的了
These memories can only be shared by us.
有个only会更亲切,感觉很怀旧
That's the old time, only belong to you and me.