When we give unconditionally, is there more going on than just a trade of resources?
In life all you truly have is who you are and how you feel about yourself. Anything in your external life, e.g. your finances, your social life and relationships, is a result of who you are, not the other way round, at least in the long-term. A challenge in life is learning to accept this situation, because it is in human nature to identify yourself with your external life and hand your responsibility over to it.
So what this means is that how you feel about your life really comes down to who you are as a person. You will probably have your ups and down as your external life gives you knocks and bruises, such as the loss of a loved one or a financial crisis, but all these things are only temporary. The only thing that is really everlasting is who you are as a person.
Understanding this concept is a key difference between being a selfish person and a contributor.
Say you give something externally to someone, e.g. your time, your money, your expertise, it will cost you those things, which can be hard to deal with if you are heavily identified to your external world. However, if you look at the situation in a different way, you see that in return for giving you gain in who you are as a person and how you can feel about yourself and the world. By looking at it this way giving no longer has to be an act in which you lose out.
If you truly understand this it will open yourself up to being able to give more and enjoy it, because you know by helping someone else you are also helping yourself. This is a great way to overcome the scarcity mentality. This is also a great way to look at things for those that always have to ask "what's in it for me?" If that kind of person looks at giving in this way then a previously selfish person can become highly motivated to give.
Another way to think about this is as follows. If you give nothing the other person suffers and your character suffers. If you give something then the other person gains and your character gains. It's lose-lose or win-win, whichever decision you make.