Apparently, a common affliction of youth. The inability to picture oneself at 30, and resultant disbelief that one will live to see that age.

The landmark is so noticeable at this age, perhaps, because it takes a long time to get there. It's probable that we have similar mileposts all through our lives. That in some inarticulated way we doubt we'll ever turn ten, then maybe 18 or 21, then 30. Wherever it falls, precisely, it does seem there's another age somewhere between 10 and the end of one's teens that we cannot conceive of reaching. It seems likely that one has a similar feeling of questioning maybe about age 60, or 80.

Someone's probably said all this before.

Our picture of ourself changes rapidly during childhood, and only just begins to settle down during puberty. By 20, maybe we've got a little bit, just a very basic conscious concept of who we are. At 30, I presume, we have more faith in our knowledge of ourselves, we've started to really know what we want to do or where we want to go, even if we're not entirely ready to commit to those pursuits. Of course, as the process of personal change slows down, it should become easier and easier to picture oneself multiple decades down the line, as most future changes will be in terms of physical appearance or experiences accrued.

I realized today I'm probably not going to die when I'm 30. Rather, prole the 30 year old will look back and be amazed that she is the same person as prole the 21 year old, the same way prole the 21 year old now feels about prole the 12 year old and is starting to feel about prole the 17 year old. Maybe by the time I hit 40, I'll be able to look back a decade and relate to myself.