Wine, wine, and more wine (and some food)

I know that it is very obvious that the characters in this book drink as if there were no tomorrow. But because of how much wine and alcohol is mentioned in this book, I thought that it would be a good idea to dedicate a post to it. One thing that I am confused about is whether or not that alcohol really is such a big part of Europe's culture. The characters of the book will go and drink at a bar, then go eat at a restaurant, then go drink at a few more bars, then eat again, and so on. It seems as if their only purpose in life were to drink, and this would mean that the characters in this book are supposed to have no purpose. For example, at the end of chapter of 11 on page 116, Jake and Bill are getting a hotel and the Jake believes that the price to stay there is too high. But then he asks, "Is the wine included?" And she replies, "Oh, yes." And because of this, Jake decides to stay at the hotel. I'm sure that he'll get his money's worth of wine.