[Psa 51:6 NLT] (6) But you desire honesty from the womb, teaching me wisdom even there.
Other translations render more literally as "hidden part" instead of "womb".
I'm wondering if this might be an allusion to the Psalm:
[2Ti 3:13-17 KJV] (13) But evil men and seducers shall wax worse and worse, deceiving, and being deceived. (14) But continue thou in the things which thou hast learned and hast been assured of, knowing of whom thou hast learned them; (15) And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus. (16) All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: (17) That the man of God may be perfect, throughly furnished unto all good works.
If so, then the one who taught Timothy is God ("they shall all be taught of God") and he learned them as an unborn child by his receiving the divine breath. In which case Paul's reference to "God-breathed" may mean "by direct revelation". And of course Timothy need not be embarassed by his lack of human training.