...is that it's full of surprises.
For example, my shape is shifting, like the Companion in the ST:TOS episode "Metamorphosis" but without the power, naturally. I'm still slim, but somehow some of my pants aren't fitting quite so well. And it's not merely that they're tighter, but they're tighter in places that used to be not tight, and loose in areas where it used to be tight.
Another example is my disposition. I'm definitely less grumpy than I used to be, and I'm not grumpy for nearly as long. I don't know if it's just that I'm losing my short-term memory and therefore can't maintain the level of annoyance it takes to remain angry, or if I'm happier overall (I know, I know, you probably couldn't tell from all the complaining that I'm doing here).
"To be conscious that you are ignorant is a great step to knowledge." ~ Benjamin Disraeli (1804 - 1881)