There is an old expression in basketball - "You can't teach height".
I often think about this in the context of a לב טוב. I wouldn't say that it can't be learned and assimilated into a personality but if one doesn't have it naturally it takes a lot of work.
I know people who *keep all the rules* but לב טוב - אין. I have known people who aren't careful about *all the rules* but have beautiful hearts.
It is a precious trait. [עי' אבות ב ט]. We are soon going to start counting the Omer which is about developing a לב טוב [do the math...].
It begins with self-awareness. A person has to see where he is holding with regard to this middah. Then work [no matter what the point of departure is] to constantly enhance this middah within oneself.
