My comfort level in my own skin has changed over time as I've gotten older.
When I was a teenager, as with most female teens, I was obsessed with being thinner, more buxom, and generally more "pretty" than I was at the time. And a teenage female never thinks she's pretty by any standard! :)
As a middle-aged adult, I'm extremely comfortable with my body because if someone doesn't like me for what's on the inside of my skin, they aren't worth the time it would take to get to know them. On Christmas, you didn't keep all your presents nicely wrapped and stare dreamily at them, did you? Heck no...you ripped 'em open to see what was inside.
I'm slightly overweight and gravity enjoys tormenting certain parts of my body these days. I also have a few gray hairs, stretch marks, and wrinkles. They don't bother me because they AREN'T me. They are just the covering on top of what is really important, and that's my mind, heart, and soul.