Once the creator was thinking about where to conceal 'that' wisdom after attaining which nothing is left to be attained. His wife suggests a high mountain or a deep sea but both were discarded as man can climb or swim. It was then decided to keep this wisdom inside man, while man searches for it outside for lifetimes. This metaphor makes it easy for us to understand when Krishna says, "Certainly, nothing in this world is as sanctifying as wisdom. In due course of time, he who perfected in yoga finds it in the self" (3.38). The essence is that 'wisdom' is in the self and by the same measure everyone has it. It's just the question of realising it both in self and others.
Krishna further says, "Shraddha-vaan (one with Shraddha) and Jitendriya (one who won senses) obtain wisdom leading to parama-shanti (supreme peace)" (3.39). Krishna gives contrast and says, "The ignorant, devoid of Shraddha is ruined and there is no happiness for him in this world or other." (3.40)
'Shraddha' is a common thread in the Gita. Devotion, trust or positive thinking are its closest meanings. Krishna talks about Shraddha at many places and encourages Arjun to be Shraddha-vaan. Shraddha is not a ritual to get the fruits of action of our choice but inner strength to accept with gratitude that whatever comes our way is the best thing that could have happened to us in the given circumstances however adverse it might be realising that we can't have separate desires than of existence.
Making senses subservient is an integral part of the Gita. Krishna elsewhere compares senses with wild horses and tells us to control them like a trainer who rides horses by understanding them. Certainly, it is understanding but not suppression.
Source - Daily World