A single man, no matter how productive, can only do so much by himself. If he turns his labors to inspiring others, his limit of contribution will expand to include the amplified works of those he inspires. If he can show them, in turn, how to inspire others, his contribution becomes unlimited. Likewise, as long as your sense of happiness is derived from what you alone feel, your happiness will be limited--finite. When you learn to rejoice in the joy of others, your happiness becomes unlimited. It is THE way you achieve unlimited happiness--there is no other way. With that vicarious capability comes the necessary opposite--you also feel the sorrow of others. If you have understanding that exceeds theirs, you will feel commensurately greater sorrow, because you will be aware of all the things they are doing and not doing that detract from their happiness. They may be lumbering along in blindness to the fact that they are about to encounter some awful things that they could avoid if they just put their trust in truth. You will feel all the pain of what they have not yet experienced, plus more because you will know it could be avoided. For you, it will be as if it is already occurring, even if it is a future event.
I have been subjected to all types of grief, pain, and sorrow throughout my life. I am no stranger to it. Some people are overcome by negative feedback from others. Intense hatred will be levied on you quite early on in your attempts to live according to what God has revealed to you. If this is a block to you, you won't get very far until you overcome it through trust in God. Some people are overcome by physical pain. It is a rare case that a man or woman of God gets through life without acquiring permanent thorns in the flesh. If this is a block to you, you will only be able to come up so far before you quit. Some people are overcome by emotional pain--depression, anxiety, sorrow, etc. In my experience, this type of pain can exceed physical pain in intensity. It seems to take more emotional pain to kill you than it does physical pain. I have spoken about depression and anxiety before--these are effects with known causes and they can be cured by addressing them. Sorrow is a different ball of wax.
The greatest pain I am aware of is the pain of knowing someone's potential and seeing them act contrary to it. And the more understanding the observer has, the greater the pain is.
I once asked the Lord why he had opened my eyes to see the potential of others. He said so that I would do more in attempting to help them fulfill it than I would if I only saw was what others saw in them. The reverse pendulum swing comes with it: a depth of pain and sorrow for them that is impossible to describe. This creates an interesting cycle. On the one hand, I try with all my might to help them. On the other, the harder I try, the more it hurts. Guess how many have lived up to their potential since the Lord opened my eyes to this? But I just keep going.
Success in life is not measured by how many people listen, or to what degree, but rather whether or not we do all we can to acquire and attempt to share what we have been given. It is what we give and not what is received that matters.