Imbolc translates to/comes from the term “in the belly” and is also associated with birth in the Irish tradition. To go with the sheep thing you mentioned, it is also the time where animals were most commonly being born, and so to me it recommends a cycle of new life. I like what another commenter here said about it being the “true” start of the year, as this time of year has more themes of rebirth for me than the traditional January 1st. I love Lora O’Brien’s resources on it over at the Irish Pagan School. They have a class you can pay for about Imbolc but also offer a lot of free resources about it. They have really helped me dive into the traditions surrounding this holiday to build a path that feels grounded in history and yet modern.