I once brew a beer that I called "The Big Monster RIS", it was ~18%, I still have a few bottles left, I think. I opened one a couple of years back and shared it with several that were there and all said OMG this is amazing, sell me a bottle or two they said, nope, no can do. It was a couple of years prior to that I had opened one a shared it with several friends as well, all had a similar reaction.
I fellow came over and the plan was to brew a RIS (10 gallons), and he kept asking "What can we do to make it bigger/stronger?"
Well more grain and more molasses would make it bigger, it ended up being 80+ pounds of grain and who know how much molasses, also did a partigyle and got 10-15 gallons more of smaller beers, I don't recall as I gave them to him. We started out with WLP006 and ordered several vials of WLP099 and I added them when they came in, amazingly the beer did finish, it was truly awesome.
When he took his share home, I told him, this needs to age for at least 3-6 months. He came by a couple of weeks later, saying he was going camping with his re-enactment group. He told me that he was taking beer with him to share. I asked did he have some of the big beer with him, I knew he did, he responded, why of course, he pulled out a container and poured me a bit, and complained that it was flat. It was mighty tasty at that time. I then reminded him that I had told him that it needed to age 3-6 months minimum, on gas so that it could continue to meld and carbonate. He was like, well I just wanted some. No self control what so ever. Really big beers need so much longer to carbonate.
I've tried a time or two to get something close, it was never the same. One was highly under attenuated, I tried everything I knew to get it down, it just didn't happen. I gave some away, bottled some, there may be a few bottle around, and I believe that I dumped some as well.