One doesn't understand what is moral unless they interact with others. A person that has never had to answer for their actions in any way has no concept of what is right or what is wrong. Once you interact with another person, any transgression you commit gets a reaction from the other person. Multiply this by a whole society and a consensus emerges of what is acceptable to the society at large.
Now what is accepted as moral by the society depends on the society. Thus "morals" are dynamic. They change over time. They are different among different societies.
There is not an innate sense of morality. Morality is learned.