I enjoy mushrooms alone, for introspective trips but at rather high dosages...
One night after having consumed around 12 or 13 grams (I had 14 and gave two or three to my father) I had a great introspective experience that ultimately ended in ego death laying on my kitchen floor at 3am.
As was stated before, it can be difficult and you can get into negative thought loops, but I find that usually happens as the trip drags on. I had wonderful thoughtflow and floods of forgotten memories which were like lost gems,for nearly six hours. Eventually though, as I lay in the dark, on the edge of sleep, completely exhausted but obviously still unable, all outward stimulus seemed to fade away and I could see the workings of my psyche..Almost like clockwork. It's hard to grasp now. But this was when my ego had dissolved, and I hadn't noticed it. It was bliss, but with the primal psychotic mushroom twist if you know what I mean.
I'm in need of another one of those experiences. The important thing though is to always have someone you can talk to who can ground you if you need it. The worst thing on a mushroom trip is when you think you're going insane and you need to talk to someone other than yourself of the voices in your head.