Good advice, but it depends. Some people don’t want to show a gap in their resume, for any reason. It all depends on the story you want to tell. If you think the experience is directly relevant to the story you are looking to tell, put it in.

Did you do some temp work in your field for few months between full-time gigs? Probably best to include that, especially if you learned or applied relevant skills. Did you end up working in a different field to make ends meet instead? Probably best to leave that out, unless you can relate that unrelated experience to what you want to do now.