This was a very interesting thread. I have absolutely no idea what my BG was at diagnosis since I was 2 and that was 42 years ago However, my mom did say I was really sick which is why I was in the hospital and where I was diagnosed (I assume in DKA also).
So either the education I received which was very good thanks to my mom, or just how type A I am about myself, I don't remember BGs any higher than around 250 my entire life. One time I had an expired insulin bottle (boy wasn't that a good reminder) and maybe a couple times I overdid carbs/sugar/etc (as a youngin, the focus on carbs was non-existent) .
Seeing these numbers is really scary! My first reaction is being that high is cooking internal organs (this is the repeating thought I use to remind myself to be vigilant)....eeek! I hope everyone did not experience lasting negative consequences!