Experience does help prepare for dealing with culture shock and a traveler on an extended trip through multiple countries is generally able to handle it well. What comes as a surprise however, is a feeling of discomfort returning to familiar environment of home. This situation is referred to as reverse culture shock.
It's always been an interesting and well-debated question among budget travellers and everyone has their own opinion: "Do I need a sleeping bag for my trip?" To answer this, we probably need to look at the most important word in the question: "need." In other words, is it an essential part of your travel kit?