[Vocabulary] What is the meaning of "knock you on your butt"?

[mokbon]

Hello

------------------------------------------
Will : United States of America: A Complete History, Volume l. Jesus. If you wanna read a real history book, read Howard Zinn's A People's History in the United States. That book'll knock you on your butt.
- Good will hunting
------------------------------------------

In this context, Does "knock" mean "hit" and "on your butt" mean "sitting down"?

 

[susiedqq]

It will be powerful - you will be so impressed that you will feel overwhelmed, as though you have been knocked down and landed on your backside.