Hit (one) like a ton of bricks American informal verb phrase
To have a strong emotional impact on someone
The loss of her job has hit her like a ton of bricks. She has no idea how to manage to survive.
My parents' divorce hit me like a ton of bricks.
The news that he's got cancer in his stomach hit him like a ton of bricks.
The verb “hit" should be conjugated according to its tense.
This expression originated in early nineteenth-century America as “a thousand of brick” presumably because bricks in such quantity were more commonly counted than weighed. Sometime in the early twentieth century, it was replaced by "ton'', which has survived.
This phrase is used to describe something very modern or updated or something that no longer looks like what it's used to.
It has been a long time since I left my high school, and now I have to admit that it's certainly not your father's high school anymore.