That's what a lot of people don't realize...the difference between idly "wishing" for something and really deciding you WANT it.
Wishing is just that...if suddenly you had a million dollars, you would prefer it to your current state. If you had 6-pack abs, you would prefer it to your current state. But the idea behind a wish is that it's granted without any effort from you.
When you really, REALLY want something, you're willing to make sacrifices to get it.
Fitness is the classic example. Each and every one of us has the potential to be fit and strong, to lose all that visceral bodyfat and be some form or shape of "Adonis".
The things is, when you tell people what they need to do to acquire that fit shape, the work in their mind outweighs the benefits of having that level of fitness. They typically enjoy food or "laziness" far too much to sacrifice it to get the body they want.
That's not a problem in itself...if food is more important to you than fitness, then more power to you.
HOWEVER, the problem lies when they get bitter at those who ARE fit, who HAVE put in the work, have made the sacrifices, and have achieved that goal. Realistically, the person who chooses a life of sloth and gluttony should be saying, "Yes, it would be nice to look like that, but I am willing to sacrifice that for my love of food." Or they would sacrifice their love of food and sleep for the goal and achieve it.
Instead, they put down those who have made it that far. "Look at those people...they are lucky to have such good genes", or, "those meatheads...they must be juicing".
http://www.gymjones.com/knowledge.php?id=36
Worse are the people who go halfway. The ones who sign up for gym memberships, jump on the elliptical for 10 minutes and throw around a few 2lb weights and then wonder, "Why am I not getting thinner? I'm doing the work!" as they stuff a Big Mac in their faces.
There's an old Koan that talks about how a master and his student were walking by a lake and the student began talking about how much he desired enlightenment. So the master took the student's head and shoved it into the lake until the student thrashed and started to drown, then the master pulled his head back above the water. He then asked the disciple, "what did you desire most when you were under the water?". The disciple replied, "air, of course!" And the master responded, "When you desire enlightenment as much as you desired air, you will find it."
Wealth is often the same way. Everyone WISHES they were rich, but few people actually WANT to be rich.
There's some merit to that perspective...there are people who have sacrificed their entire lives for wealth in their later years, but now find themselves too old to enjoy it, having worked away their "best years" busting arse trying to make those millions.
I accepted long ago that to truly bring large amounts of wealth into my life, I was going to have to find a way that I enjoyed...I know my own limitations and I know that I won't have the drive and motivation to continue at something if I am not truly passionate about it...I will falter. I could force myself to do something I hate to try to make that "bank", but I would hate my life and wake up every morning wanting to put a bullet in my head...that's no way to live. We're on this planet for a limited time.
There are people who CAN do that...just doing business and making money is enough for them. They don't CARE what the business is. That is certainly an enviable trait. And those people are financially successful more often than not.
In answer to the original question...I've thought before about trying to be "homeless" for a week or a month, just trying it out to see how I could survive. Then going back to "real life". It's only been an idle thought, though. I don't think I'd learn enough from it for it to really benefit me, and it would derail me from the other things I enjoy doing in life.
But you're absolutely right. Even taking SMALL steps out of your comfort zone in life can be a beneficial experience.