In the millions of years of evolution that humans have been through, the moment when we realized that the future exists was quite significant. This idea cannot be emphasized enough.
Other animals do not have a concept of the future. They live day by day and only live on survival mode.
However, the human brain has developed enough that one can grasp that there is actually a tomorrow. So, one realizes that by making some sacrifice today, the future can be made better.
Thus humans work and save and build families so that they can live comfortably in the future. Humans could then move from mere survival mode to the comfort & prosperity mode. This is thanks to the millions of years of evolution of our brains and the development of consciousness to what it is today.