Richard Osman, the British television presenter and author, has not extensively discussed the impact of his father leaving during his childhood in the publicly available information I have.
It's important to respect an individual's privacy and not make assumptions about their personal experiences without direct knowledge or confirmation. If Richard Osman has shared his feelings and experiences regarding his father leaving in interviews, memoirs, or public statements, it would be best to refer to those sources for a more accurate understanding of how this event affected him.
It's essential to remember that experiences from childhood, such as a parent leaving, can have a profound impact on a person's emotional well-being and development. Such experiences can shape their personality, relationships, and life trajectory in various ways. If Richard Osman has chosen to discuss this aspect of his life publicly, it can provide insights into how he coped with the situation and how it influenced his journey.