"Sweet dreams" is a <a href="https://en.wikipedia.org/wiki/clich%C3%A9" class="extiw" title="en:cliché">cliché</a> expression.
<a href="//commons.wikimedia.org/wiki/User:Raimundo_Pastor" title="User:Raimundo Pastor">Raimundo Pastor</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>