How does it happen, Maecenas, that no one is content with...

How does it happen, Maecenas, that no one is content with that lot in life which he has chosen, or which chance has thrown in his way, but praises those who follow a different course? [Lat., Qui fit, Maecenas, ut nemo quam sibi sortem, Seu ratio dederit, seu fors objecerit, illa Contentus vivat? laudet diversa sequentes.]