Bhagavad-Gita is the most beautiful, perhaps the only true philosophical song existing in any known tongue' - so opined William von Humboldt. Though it is a matter of consensus that Bhagvad-Gita in the present length of seven hundred verses has many an interpolation to it, but no meaningful attempt has ever been made...
Psychology, if it's your cup of tea, opens doors to a lot of interesting characteristics and traits that human beings encompass. Reading about it will not only give a meaningful perspective to how you see the world, but will also allow you to reach out and understand people around you better.