This verse is about taking an unshakable faith into old age. Caleb is 85 and as fit as a fiddle both physically and spiritually. He is ready to take on a new challenge based on the promises of God.
As yet I am as strong this day as on the day that Moses sent me; just as my strength was then, so now is my strength for war, both for going out and for coming in.
No, sometimes the demands are too much for you alone, but when God is placed into the equation, the solution becomes doable.
Go get ‘em.
Gary