I think I always have been. Pessimists call themselves realists; optimists call them (us) .... pessimists.
We pessimists know the score. We know we're all heading in the same direction, and we could get there any minute. We know that every time we get in a car, that journey could be our (or worse. Someone else's) last; that that lump/cough/weight loss/chest pain is almost certainly going to prove fatal (actually, I'm not a hypochondriac, but many of us pessimists are). We know that when we invite people to dinner, that dish that's supposed to set in a pretty shape is going to tumble out of its tin in a messy heap, someone at the table will be allergic to something, and the guests will take an instant dislike to each other. (This last happened some years ago, when I stupidly invited very left-wing friends together with very public school right-wingers. They hated each other on sight. Why didn't I see that coming?). We know that that garment we hanker after will be out of stock/only available in tiny or outsize/or just won't fit. If we do buy it, it will certainly be half price in the sale next day. C'est las vie (or the pessimist's vie, anyway). Oh, and if we see a police car, of course it's after us, although we can't remember doing anything wrong.
The other day, I came across this spectacularly silly rhyme, written when I was probably about nineteen:
Oh cabbage in your cabbage patch,
Where bugs and caterpillars hatch.
Tell me, I pray, is it too late
For me to come and vegetate?
It's seems I haven't changed much.