What think is due to us being cut off from our emotions (Not entirely, just less than NTs), we tend to feel what they feel to a lesser degree. Also, I would say I feel them extremely strongly, I just can't identify them so I go months to years without realizing anything is wrong. Usually I get severe apathy and depression and I don't know what's causing it, until someone tells me someone I knew just died, then somehow that awakens me to the reality, but I still don't understand what I'm feeling.
Also, I don't know if this is true and I doubt it to be honest, and this is a very heartless answer, but I believe that a lot of stronger emotions that neurotypicals display are for attention and bonding purposes. Often things like extreme excitement, happiness, or sadness are to communicate with others. For example, when someone who they don't even know (like a celebrity, etc) dies, and they go into severe supposed depression for years. I can't possibly relate to that so I am hesitant to believe this theory, but if it is indeed true then the second reason for US feeling this way is that we don't use social signals to convey the pain and sadness, so as a result we don't blow it out of proportion and we're faster to accept it. Feel free to disagree with anything