"return to the life of the world and desires?"

From a seeker of self-realization, Siddhartha becomes a pleasure-seeker, entering the hedonistic world of the courtesan and the businessman. From the path of the ascetics, he enters the path of desires.

Householders, who also seek enlightenment cannot abandon all worldly concerns. The way of the householder is in the world and through the world, through  particular functions, natures, and talents. Rather than giving up the world, householders or lay men can explore, express, and fulfill our purpose in the world.

Mahayana Buddhism encourages the lay people as well as the monks and nuns (Sangha) to become Bodhisattvas. The Vimalakirti Nidesa Sutra is dwells on the concept of the enlightened householder.