Is there any good book on Mahabharata which explains the psychology behind the stories with real life lessons ? Thanks
It will vary by tradition but I would recommend Sanyal Mahasay's Gita. It breaks down the symbolism of the different Mahabharat characters and what they represent within each sadhaka. The "real life lessons" are taught through sadhana that needs to be learned from Guru.
His Gita is available in Hindi- http://indianmind.co.in/books/srimadbhagavadgita-3-vols-in-hindi
Also in English (but Hindi version is better if you can read)- https://www.abebooks.com/Spiritual-Gita-3-Vols-Set-Shyamacharan-Lahiris/209683059/bd