The phrase "be struck by/with something" can be replaced with a variety of synonyms to express surprise, wonder, or shock. Options include "be amazed by," "be awed by," "be impressed by," "be stunned by," "be taken aback by," "be dumbfounded by," "be gobsmacked by," and "be floored by." Each of these options conveys a similar feeling and can be used in different contexts to describe being taken aback by something unexpected, being impressed by a complete surprise, or being struck with awe and wonder by something truly incredible. Choosing the right synonym depends on the specific situation and the intended tone of the message.