Like many Zepplin songs, Misty Mountain Hop utilizes a simple, yet powerful and intriguing repetitive riff (this one only 4 beats). Each verse is sung in a nonchalant, somewhat off key frat boy sing along style, with Plant belting out the last line of the verse with contrasting clarity and gut wrenching emotion.
At first glance the meaning seems simple enough, but it addresses an underlying issue that is near and dear to most teenager's hearts.
The narrator runs into some hippy flower children (representing the free spirited anti-establishment folk) and gets wrapped up into what they are doing. But then a policeman (representing the establishment) comes along and tries to show them the benefits of the straight and narrow, "would we care to all get in line."
The narrator is confused by these two opposing lifestyles and can't decide, which path to take, "which way the pressure lies."
So he decides what he is going to do, he decides to rejects both lifestyles and get out of there, "packing my bags for the Misty Mountains."
This conflicting lifestyle choice is a constant high school and college theme, where young people are trying to decide their own lifestyle preference and feeling pressure from the free spirit group and the establishment telling them to get in line.
