Ketu is the planet of deep focus, spirituality, and isolation. The 1st house (Lagna) represents the self and the physical body.
When Ketu sits in the 1st house in a positive state ("phoolon sa mehakta"βsmelling like flowers), the person is highly introverted but incredibly focused. Lal Kitab gives a beautiful childhood *Nishaniya* (sign) for this placement: They were always the student sitting on the very first bench in the classroom.
They do not care about back-bench gossip or causing trouble. They want to be as close to the teacher (Jupiter/knowledge) as possible. Their focus is absolute, making them brilliant scholars and deep thinkers later in life.