The days of the caboose are gone. I have noticed all the trains over the last decade at least contain no red end-car or caboose. Whether it is meant to or not - this lack of the end-car gives me a sense of non-closure. I guess one could look at the train another way - you can always add-on a new car. But, at least in this age, everything has it's season then ends - as should a train on a track with a caboose.
Closure is important. Closure is healthy. Closure allows for something new to hit "the tracks" and see where it takes you. A lot of our closure is defined by age. Our teens come to a close and young adulthood begins around eighteen. Then from this age, according to the individual and society, there are different benchmarks like manhood/womanhood which are closed by age.
For the Christian there is closure on an old life and the beginning of a new one when he accepts Christ Jesus as his Lord and Savior. In the future, there will be closure on this corruptible body and Christians will be transformed to incorruptible bodies (1 Corinthians 15:53). The old world government will end and give way to the new ruler of the world - King Jesus (Revelation 19:11-21). Then a period known as the Millennial Reign of Christ, a physical, one-thousand year rule of this planet from elevated Jerusalem will transpire (Revelation 20:1-6). This too will end. A few more events take place like - The Great White Throne Judgment, the introduction of New Jerusalem, and the witness of God's creation of a new Heaven and a new Earth. Then there is no end-car.
It is hard to grasp the concept of eternity because it never stops. But, I think living in the next chapter of existence with my Savior, Friend, and Lord - Christ Jesus - will bring me closure on the need for the end-car or The Caboose.