Of thousands of men, hardly anyone tries for ‘Siddhi, which is metaphysical perfection. Of those, few succeed. Of those perfected ones, hardly anyone attains true knowledge of substances (Called Tatwa-Gyan, which is fundamental knowledge of a particular subject matter or phenomenon etc.)
The knower of facts and truth can distinguish between qualities driven actions, O’ mighty-armed (Arjun)! While sailing through realms of triguna qualities they do not stick to them (as they realize snares of nature).
The knowers of truth (Tattwa vetta) can sense various driving forces of a cause and actions under Triguna-led delusion and thus exercise self-control. Even when traversing through them (coming across different types of people, circumstances, opportunities and threats) they do not get carried away. They distinguish between doable and non-doable.