Have you ever wondered why Mercury gets Diblaba in the 1st house?
Mercury is an adaptive Graha, he is an eternal child and student, and Lagna represent a person himself, they way the person thinks and behaves, and how his or her brain works.
In the natural zodiac, Mercury rules the 3rd (Gemini) and 6th (Virgo) house, forming a natural Dhimanta Yoga (combination of having knowledge).
But learning is not only about the possession of knowledge and information. This is the ability to adapt to surrounding circumstances, this is flexibility and quickness of thinking.
Together with the Digbala of Jupiter (truth, eternal knowledge, principles and ideals) in the first house, this allows one to intelligently adapt without betraying oneself and thereby maintaining one's own strength.
In addition, Digbala is associated with Muladhara (root) Chakra, which tells us that this is an important quality for survival, as well as the ability to distinguish: what is really good for one and what is bad.