Ever since Luke left her Annabeth kept her feelings locked up inside her. She wouldn't let anyone get close to her or simply make her happy. For a year she hid, ducking under cover or building her own walls where no one could find her. Not even the Son of the Sea God with messy black hair and startling green eyes.
At one point after they won the chariot race she felt herself slip and let herself kiss Percy on the cheek. Only later did she realize that simple gesture showed affection and once again, she went into hiding.
Then the year they went into the Labyrinth was the year she was found . Percy found her hiding place and he tore it down. However, she wasn't mad and she realized deep down that was what she wanted to happen the whole time.
Thanks to Percy her walls were finally gone.
