Life in this world is like a fixed-term rented apartment with a non-renewable lease. When your time's up, you pack your bags and out you go.
In this world, all of us are renters. Hashem's the landlord, and he gives us our bodies as temporary shelters for the soul, so that we can accumulate the gems of Torah knowledge and good deeds that will be valuable to us in the next world.
As renters, we have to pay the rent. If we're smart, we happily fulfill our obligations before the landlord comes pounding on our door. If we don't pay our rent in this world, we pay a severe penalty in the next world.
Succoth reminds us that we all live in temporary quarters, and that we're all at the mercy of The Great Landlord. We have to express our sincere gratitude for every single day that He extends our lease; that's why we need to utilize every single minute for Torah and mitzvot, because we never know when the non-renewable lease terminates.
Big Beam blessings for a joyful Succot holiday!