Many a learned people after intense study suddenly lose their interest in philosophy, ask them any question they would be in a position to answer, yet they will not have drive to put it in practice. The ususal excuse will ,now i know everything ,so what's next. Next is sadhana. A vidya when obtained , should be attained perfection ie siddhi, with siddhi comes application , with application comes sakshatkar.
The more you know more will be your sadhana. it is strange to observe that a most gyani attains Moksha late , and lesser souls attain Moksha fatser . because lesser souls have less sadhana, higher souls have greater sadhana . Many struggle to even get the knowledge , so sadhana starts after many kalpas. But Vayu Deva knows everything from srujya avastha itself yet he has sadhana of 100 kalpas. What he does in his 100 kalpa sadhana is nothing new to learn but shastras says ,rujus are 'anubhav rahita's ' and thus they do sadhana. Their linga dehas are like that of burnt shirt. where it does not affect them , simple shake is enough to get rid of samsara. Hence they are always happy , among parashuklatraya.