Deep inside us, there is a sense of something more in life that drives us forward. No matter what experiences you've had, no matter how wonderful they were, they were just a glimpse of what is still ahead. You are homesick for a world you're not in, Heaven. You are wired for it.
The Bible says that God has put eternity in our hearts (Ecc 3:11). This means there is a sense inside of us that there is more to life! That is what keeps us traveling down the path forward, a sort of homing instinct for a we long to see.
The hope in following Jesus is a better world ahead.