in general in the whole world real happiness comes from accomplishing, growing, improving, creating, and nothing else.
however even this happiness is short-lived and superficial. but it causes happiness because it comes from the deep inner desire to come close to Hashem that was implanted in all men when Hashem blew the breath of life into us from Himself.
only without the Torah the drive to accomplish becomes woefully distorted and manifests itself in building businesses, climbing mountains, flying around the world, yoga, meditation and self-help books.