I never feared 19. I'm Canadian, 19 was drinking age! My mother warned me that I'd fall into a deep depression at 30, never happened. 40 came and went, nothing. then, last July, 50...BOOM! I lost my shit! I wrote all about it. But long story short, I freaked out. All of a sudden, I was on the downslope, every ache, ever sensation was a possible symptom of dread disease. I'd test myself, just to make sure I could still run or do cartwheels. I implemented a strict health food regimen, that lasted 4 days. Then I got over it.
I like being 50. I've lost over a dozen school friends in the last few years, so the half century beats the alternative. But do I miss that smooth-faced wisp of a girl I once was, yeah, sometimes. But hey, they're still asking me for ID when I buy wine, so I'm good. :)