This was overheard at a meeting. It’s a nice mashup of the phrases “went over like a lead balloon” (to fail completely or go over badly) and I think “it hit me like a ton of bricks” (surprised or shocked). “Drop a brick” (to announce a surprising bit of news) might also be in the mix. And yes, lead bricks are manufactured – see http://ultraray.com/products/lead-bricks?utm_source=bing&utm_medium=cpc&utm_campaign=Ultraray&utm_term=lead%20bricks&utm_content=Lead%20Bricks
A big thank you to Jenny Hensley who dropped this one on me!
The speaker was talking about how difficult a final exam was. Given the context, this is a mash up of “hit me like a ton of bricks” (to surprise or shock someone) and “hit a wall” (coming up against an insurmountable obstacle). The exam must have been difficult and a surprise! The confusion is obvious: both expressions contain the word “hit” and certainly walls can be made of bricks. The expression “hit a wall” is also sometimes stated “hit a brick wall”, making the two expressions have even more commonality. Perhaps the speaker is a Pink Floyd fan as well. A big thanks to Adam Jacob for hearing this one and passing it on.