"Hope deferred makes the heart sick, but when the desire comes, it is a tree of life."
So many people work for money. They get out of school and find a good paying job and get stuck. They might look for a promotion but even then it is just to 'move up the ladder' and ultimately to get more money. They set their desires aside because they have to 'earn a living'. Our society often looks down on dreamers as people who are lazy and not willing to work. This attitude gets a lot of dreamers stuck in jobs that they hate, working hard to provide for their families, and living for that day off or that vacation, hoping that one day they can retire and finally do what they love.
I believe that this is what Solomon was talking about here. "Hope deferred makes the heart sick..." When we set aside our desires it is like setting aside our hope and ultimately makes us sick. We find ourselves struggling to enjoy life and spending most of our time just waiting to get a day off. But when we find that desire, when we find that ability to do what we love, we plant a seed that sprouts into a tree of life. Jesus said that He came to give us abundant life (John 10:10). I believe that this is one way He does that. He gives us the ability to live in our passion, but sometimes we do have to work for it. Sometimes we have to make a sacrifice.
Proverbs 14:4 says "Where no oxen are, the trough is clean; but much increase comes from the strength of an ox." In other words, sometimes in order to move forward we have to be willing to do some dirty work. We can be content with a small farm where we plow it ourselves without the oxen. In that situation we don't have to worry about feeding the animal or cleaning up after it but we won't ever grow. If we want to expand our farm we have to suck it in and get ready to clean up some poo. Sometimes it is the same thing when we are going after our desires. Sometimes we have to suck it in and put in some extra work. Sometimes we have to work two jobs because the one we love isn't paying enough. Sometimes we have to sacrifice some of our free time to put work into that thing that we love, but if we put in this extra work we will find that we will get "much increase". It won't be long until we find ourselves in the place that we want to be and we find ourselves with a "tree of life".