The phrase "to see the inside" means to gain a deep understanding or knowledge about something or someone. It refers to looking beyond the surface or appearance and discovering the true nature, thoughts, or feelings within. Full definition
Most personal injury lawsuits don't see the inside of a courtroom because of the time and money associated with litigation. (philadelphiapersonalinjuryblog.com)
Like I haven't seen the inside of a repair shop since we got married (praise the lord). (climbinggriermountain.com)
My children's books never saw the inside of a bookstore. (sciencemag.org)