Among other meanings, Moon represents our mother. Or more specifically, our perception of our Moon, which may be different from our sibling's or our mother's friends, colleagues, etc. When Moon is in Capricorn, it could suggest that we perceive our mother as controlling, not very forthcoming in her love for us. Because of that, our childhood might be felt as restrictive or limited in nurture. As that's the environment that we possibly grew up in, psychology suggests that our upbringing affects who we are as a person.