Kohut jives with my experience. My mother was in the hospital for a brain operation a couple months before I was 2 and I just "sense" stuff and my first memory is from around there (I got lost and my father "found" me) but I had a heck of a time working in therapy for a couple years because it was all 2 year old through 4-5 year old and there's not a whole lot of words there yet. My mother had aphasia when she came home from the hospital, would come up with the "wrong" word ("hand me my elephant" instead of "comb") and I was just 2 and learning to talk; I still have trouble when I get anxious or excited, lose words or get them jumbled. I went through a phase where I had to correct the world's grammar, spelling, and other word mistakes; figured out if you made mistakes with language I had to correct it or you'd die :-(

Maybe people have different "bottoms" depending on their life experiences and when things started/got bent and what went exactly went wrong? I have an odd, personal theory, too long now to know anymore if it's really "true" but I started gaining weight as I started getting better in therapy (was 127 pounds when I started therapy and am now 270) and feel like I "moved" myself into my weight in order to move out of my head and into the world. Kind of like creating my own armored vehicle :-) I let the obvious non-working psychological protections go, worked things through, didn't need them anymore, but made a different kind of physical boundary? Maybe like I have, you can make your own "bottom" theory that works for you? They're theories! Your guess for you is probably better than some "expert's" guess for you.