The phrase "was fascinated" can be replaced with a variety of different synonyms, each of which conveys a slightly different shade of meaning. For example, the phrase "was captivated" might suggest a deep and intense interest in something, while the phrase "was intrigued" might suggest a more intellectual curiosity or a desire to learn more. Other options might include "was enchanted," which implies a sense of wonder or magic, or "was spellbound," which suggests complete absorption or immersion in an experience. Ultimately, the choice of synonym will depend on the context of the sentence and the specific connotations that the writer wishes to convey.