A2A... Because people with good hearts feel pain more deeply than others. And also because others exploit such people's goodness and willingness to trust them. read more
People usually have good hearts, but most of them have bad thoughts or times which might make them do wrong things turning themselves heartless most of the times affecting the most vulnerable ones. Vulnerable ones get hurt majorly because selfless type of emotional attitude always attracts selfish practical approach driven behaviour thus striking hard. read more
If you aren't a good person (just a normal one), that has chosen good behavior as a means to avoid being hurt or as an entitlement to protection, then the hurt could be seen as being more intense when it happens. read more