When expressing surprise or disbelief, the phrase "who would have thought...?" can be replaced with a variety of synonyms. Some alternatives include "imagine that," "unbelievable," "unexpectedly," "surprisingly," "astonishingly," "remarkably," "astoundingly," "incredibly," and "unforeseen." These words not only convey surprise, but also add emphasis to the unexpected outcome. In addition, these synonyms can be used in different contexts, such as experiencing positive or negative surprises, making unexpected discoveries, or achieving unconventional goals. Using synonyms allows for more creative expression and avoids repetition in communication.