Just months after Hiccup defeated the Red Death and the village witnessed the arrival of dragons on Berk, Astrid was already having a hard time coping with things. It wasn't the dragons or her relationship with Hiccup really. It was just...her.
Since the Berkians no longer killed dragons, there was no competition over that, and Astrid felt at war with herself. She was brought up to be strong, tough, and to not be easily swayed by anyone else. If anyone crossed her path, she'd threaten them and maybe twist a limb, making her the most intimidating viking on Berk. And of course vikings were made to be tough, sometimes sarcastic and very stubborn, but Astrid felt out of place. If there was no more competition or need to make sure she was the best, then what was she supposed to do now?
Periods of depression started occurring in the fifteen year old's life, and she absolutely hated it. She felt miserable and unable to concentrate on anything. It was almost as if she was losing sight of herself when she was still trying to find it.
All the pondering of who she was and who she wanted to become was too much for her to think at the place and time. Dragons had to be trained, Berk defended, and her relationship with Hiccup stable. But if she wasn't even sure who she was herself, then all the other aspects of her life became harder and harder to deal with, and sadness involuntarily kicked in.
"Hey, Astrid," Hiccup spoke, coming from behind the girl as he took her hand in his. "How are you?"
Astrid sat down on the stone walkway, placing her head in her hands for a moment. "Fine, fine," she mumbled, and Hiccup obviously knew that wasn't true. It wasn't hard for him to catch on.
"What's going on?" he asked, taking a seat next to her as he placed a hand on her shoulder in reassurance. "You know you can tell me anything."
Astrid just sighed, lifting her hands from her tired face as she stared at the ground, not wanting to look Hiccup in the eye.
"Me. That's what's the problem."
"I-I don't understand," Hiccup explained.
"Me either," Astrid sighed as she rubbed her temples. "Lately, I've just been...depressed."
"Depressed over what?"
"I don't know. Simply because I feel that way, I guess."
"That's not an answer," Hiccup remarked, quoting the same words Astrid had used on him before. "Why are you depressed?"
Astrid rolled her eyes at Hiccup's choice of words. "There's just been a lot on my mind recently. We no longer kill dragons, so that means I don't have to make sure I'm the absolute best, and I'm just trying to find myself. I'm trying to figure out who I want to be. But we have more important things to do like train the dragons and protect ourselves from any armadas that may-"
"Astrid," Hiccup said softly, stopping her mid sentence. "Don't stress. It will take some time to adjust to all this, but eventually you will. What you're searching for is in your heart, not what anyone says you should or shouldn't be."
Astrid just kind of rolled her eyes at his "cliché" statement.
"Yes, I know it sounds cliché but you'll thank me for this pep-talk later," he finished, quickly kissing Astrid's cheek before walking back home with Toothless to turn in for the day.
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The next few days were like a blur. Astrid's depression had been worsening, and all efforts to stop that discomforting sadness failed. She had decided that taking on a relationship was too hard for her at the moment, so Astrid called Hiccup over to the cove one day and simply explained why she was breaking up with him, and he understood, but that didn't stop him from being sad himself.