This passage begins by speaking of going away to seek rest. I think that this is incredibly important, but often gets missed by focusing on other parts of this passage. We often think of God as this distant all powerful being that is so far above us that He could never understand our needs or even care about them. But God created us, and He love us completely, and He knows us better than we know ourselves. He knows that we cannot give of ourselves constantly without taking time to rest and renew. Even more, Jesus was fully God and fully man, and while He recognizes our need for rest, He too as a human man needed rest as well.
There are not many places in the bible that speak directly to the fact that Jesus had a fully human nature and so when we encounter these passages we need to take a moment and recognize them and the fact that Jesus was just like us, He felt all of our emotions, love and joy, fear and pain. He ate food and felt full, and he also fasted and felt the pangs of hunger. He gave of Himself, healed the sick, performed miracles, and poured out love and encouragement to all that He encountered, but He also rested. This is important for us to recognize that God, in the man Jesus was just like us, He knows us, and all of our concerns, and He cares about them so much that He became like us, so that He could save us from our slavery to sin.
And yes, while rest is very important to a well rounded life, and is needed for basic happiness, Jesus shows us, in the last part of this passage, that sometimes, some things are more important than our own needs and when those more important things come around we must make time for them. Every time I have read this passage, I am reminded me of being a father to young children. I can remember several times when I was about to sit down and have a meal and was stopped because of something that was immediately needed by a child, and to them it was way more important than anything else in the world. About to take that first bite of the sandwich and have to stop and set it down and deal with whatever they think needs to be handled first.
This is the call and duty of Fatherhood. Whether it is biological, or spritual fatherhood, we must rise to the occasion and take care of our duties and the needs of those that rely on us. We must put all other things aside, and tend to those things that need our foremost attention, and to do those things with love, and joy, and a spirit of generosity. This is the economy of heaven, there are no selfish and greedy people in heaven, all give completely to everyone, and as a result all are lifted up. That is a beautiful thing to think about, and to look forward to, and to work for in this world. But as you go, and do your best to bring that love and generosity into the world and all you meet, dont forget to rest, so that you can be ready for the next day.