Dear Dreissea
I definitely wouldn't mind having the experience again. I do not have many friends in my personal life, and I actually would really like to meet the young man again. Another part of the reason that I didn't want to dismiss the experience as just a dream. I would like to think that this young man is someone real and existing in the world.
If you remain open to these experiences you can enjoy more. But it is like everything else - the more we "try" to do anything, the less likely it is to happen. Remember - All is already inside us - infinite potential - but if the Ego gets in the way it screws it up

Our task is to convey an "intent" in Faith, and then step aside to allow Higher Mind to make it "real".
That young man existed alright, but he, like all the others is an Earth-bound Soul - deceased - but bound to the Earth vibration for some reason. There are millions like that - just regular people who can't let go of Earth for some reason - although they always do eventually and go to the Astral. They always have that choice. There are groups of OBE'ers who help people like that to move on. The Monroe Institute - who have never been involved with - used to do that - it is called "Soul Retrieval". There are many, many groups of Souls in the Astral who do the same - it's there way of being of service. I am sure he welcomed your presence as much as you welcomed his.
There are a few things that I thought perhaps I should have mentioned, but I didn't think about them until later in the day. I had typed this up within an hour of waking, then copy/pasted it to a few different sites. I must say that this site has given me the best feedback so far. Anyways, the other items I feel I should have mentioned:
1. This young man was the only person to interact with me. Nobody else paid me any mind. It was almost as if they did not notice I was there, or even see me.
The others were slightly out of phase with you - slightly different vibration. Would have been from different "time-lines" as well - space-time doesn't apply there. That is a very common situation in OBE - some will know you are there, some won't. Doesn't apply to the Astral because there you would always be on the same vibratory frequency. If you went to the Astral, usually it is equivalent to the Vibration of your own Soul - where you would go. In Astral and Mental Projection, you can go as "high" as your Soul and Spirit Vibrate, and can lower that frequency to visit the lower vibrations, but the opposite does not apply. We cannot increase Vibration beyond our native Spiritual Vibration.
It is different in the Etheric though. Due to the lower vibratory frequency anyone can go there, but because the vibrations are more dense, they are also more intermingled and less defined. You could have "tuned in" to the other people there - the ones that were ignoring you", but then you would have been out of phase with that young man and he wouldn't have seen you

2. I did not touch anything. It's not like I tried to touch anything, but I didn't open a door for myself or anything. The young man opened the door to his flat for me, and he was even the one who opened the fridge door. He turned on the television for me and everything.
That could have been for a number of reasons. He may have known you were slightly out of phase to those "apparent" objects, but more likely he had created them with his mind and only he could interact with them.
3. The flat we were in seemed so empty, almost like no one was living there. Like I said, the fridge had almost nothing in it. There was no furniture, and just a small tv on a small tv stand. No pans or dirty dishes. No kitchen table. Just the fridge, a stove, and a tv. There was supposedly a bed, because the young man had told me I could sleep on it, but I didn't actually see it. The place just seemed so empty, not like a house you would expect someone to be living in.
He had all he needed to stay there. After the physical there is no need to food and other earthly functions. Or you may have been slightly out of phase with the "stuff" he had and so you wouldn't be aware of them - it's the same as those other people not being aware of you. You can actually expand your frequency range to encompass the whole experience, but yours was obviously very focussed so you were only aware of him and a few other things on the same frequency band - like tuning in a TV channel. Here on Earth everything is "fixed" to the perception of the Ego, via atoms, molecules etc - Earth is designed that way so everyone can interact through the medium of the physical body, organic brain, Ego Mind etc. But even on Earth it is not "real" - it is just a "shared illusion" - it is designed that way to serve its purpose.
You can think of it like "long wave" and "short wave" TV, radio etc. Longer waves - of a higher amplitude - have a broader band of frequency fluctuations, that's why in "long wave" you can get a lot of "bleed over" from adjacent channels. With short wave/higher frequencies - such as the Astral and beyond", the frequency band is much narrower, and continues to get even narrower as you go up through the frequency range - further inwards - towards Source.
It's the same with "resolution". The higher the frequency/narrower the frequency band, the higher the resolution of the Wave. The Astral seems far more vibrant, solid and real than the physical world, and so on up through the scale. Comparing even the Astral with Earth is like comparing a moder HD/3D TV with one of those blocky, pixellated TV sets of yester-year. That's one reason why "deceased" people from the Astral only visit Earth for a very good reason - e.g. to visit someone still living here. To the people in the Astral Earth seems like a terrible place - dull, murky, crude definition - they say it is like "wading through treacle"

And of course they can feel the thoughts of the people emanating from Earth, which, to them, is a tortuous experience.
You could visit this young man again now you have his energy signature. Immediately before you fall asleep - it is a fine line - focus your mind on him with the intent to see him again.
Let us know if you have any further exeriences.
Lots of Love,
Adrian.