I want something of my own with an action. So the action gains a value for me. The action itself then becomes a means. My real purpose lies behind it.

And often it goes further:

A young man learns to drive. Why? To get a job. Why the job? To earn money. What is the money for? To start a family. So every purpose becomes a means again for a further purpose.

This can go on without end. As long as the purposes are finite, each one points beyond itself. None of them is a final purpose.

Summary: My intention makes the action a means for my purpose. Finite purposes turn into means again themselves. So a chain without end arises.

§ 420. But this universal transition, which is action in general, still contains manifold other relative identities: α) the universal will existing in and for itself is the law and the substance, in which the immediate singularity of the subject, as well as external reality in general, is sublated; it is therefore the absolute final end, the good in and for itself; duty for the subject, and the ultimate end of the world.