*Sigh* Am I being unrealistic?

Cobb_66

Hi there everyone. So, my thought is that bodies change over time - usually when you're younger. Women go from their normal teen bodies (when they can eat whatever they want and gain very little weight) to what I call "baby bearing bodies" (where you even look at food and it goes to your hips). So I have a sudden concern. I am only 20 years old - but the weight I wish to get to was the weight I had when I was 15, when I still had my slim not-gaining teen body.
So is it impossible for me to ever look like how I did when I was 15? I look at pictures of myself and that's what I'd like to be. But am I being unrealistic in this goal?