Perhaps I'm thrown off by the ready dismissal of those older than 30.

It may be a form of satire as you suggest. Such things exists. In 2008 there was a Onion headline "Junior Senator Returns From Backpacking In Scandinavia With Obnoxiously Broad Perspective On Infrastructure Reform", but I can't find a working link to it.

But satire works when there's at least a seed of truth. Consider http://totallysamsworld.com/backpacker-stereotypes/ , which lists "Backpacker Stereotypes". The last is "The ones who want to ‘find themselves’":

> These confused and emotional people have gone travelling to find themselves. They don’t know what they want to do for the rest of their lives, and all their friends are settled down, popping out babies and in great long term careers. Whereas they want to avoid commitment and responsibility for as long as possible. These backpackers can go from one extreme to the other… Living by YOLO, trying crazy new things with open minds, to getting all drunk and emoshe, crying on strangers and treating them like therapists. These guys are great when they’re on form, but if they are having a ‘moment’ it’s best to avoid them like the plague.

Here's a blog post from someone who has post-travel depression after a "year of mind-blowing adventures" - http://www.nomadicmatt.com/travel-blogs/coming-home-blues/ :

> You find your friends don’t understand the new you, don’t want to hear about your time sailing the Pacific while they sat in rush hour, or don’t get why you feel so uncomfortable being back. “What? You don’t like it here anymore?”

I think the comments help enrich the understanding of those with post-travel blues. Some choice quotes, that are not indicative of the whole, are:

> Can someone please help me cure the travel bug!! It’s ruining my life, relationships, careers and friendships!! ahhhh

> How can we not change after having experienced everything that long term travel offers? It’s hard to explain this to family and friends without sounding self righteous.

> If you don’t want to get married and start popping out babies it’s like the end of the world for some people. [I picked this one because it's almost exactly the stereotype quote from earlier.]

> What I find astounding is that many people don’t really care that I did. What to ME is an amazing thing, they don’t think much of it.

> Paul Theroux has a great quote: “You go away for a long time, and you return a different person. You never come all the way back.”

> Yep, there’s just absolutely no way that people who haven’t travelled long-term can understand what we go through.

I quoted these as examples to show that, yes, this is a real problem, that many people have to deal with. One of the ways to deal with a problem is to infer that it makes one special, perhaps like the agony of Marine Corp training makes one special, or of hazing. I believe the author's coping mechanism is to embrace the emotion pain, and the advice to others to avoid the pain is in fact a boast that the author can take the pain when others can't. "Thank you sir, may I have another!"

You believe that the original author recommends "people to not open their minds until their 40s". I don't believe the author is doing that at all. I believe the author thinks that anyone in the 40s is more set in their ways, so their minds are more closed (on average) than someone in the 20s.