Complex sentence: Donald is hit by the urn on his head and is knocked out cold when he wakes up he thinks it was just a dream but as he drives away the genie's voice is heard meaning that all of this was real.
Split into simpler sentences: Donald is hit by the urn on his head and is knocked out cold. When he wakes up, he thinks it was just a dream but as he drives away the genie's voice is heard, implying that all of this was real.