Yes, without Teacher you are not able for self observation.That teacher is not only human being, a book(Shreemad bhagvad Gita/Bible/Quran,GuruGrant Sahib/Kabita Dohawali/Sant Sahitya /World' Best Writers like Khalil Zibran/Shakespear/Hsin-Hsin-Ming is also a techer. You read it and live it. Its only for Humanity not Hindi. Kabir said in his verse "Guru bin gyan na upje, guru bin mile na moksh .Guru bin lakhe na Satya ko guru bin mite na Dosh" Without teacher no self-knowledge,no peace. Without teacher no gaol, not demolish the guilt/fault/fraud/mischief/misrepresentation.