You can't remember much from the expedition you went on. The last thing you remember is how it was a storm as you were out there, and you were separated from the Scouting Formation, as well as how your horse slipped in the rain, throwing you off, causing you to fall and break your leg and cut yourself on a sharp rock. You lost consciousness due to blood loss and mild hypothermia. And you can't remember anything.
When you woke up, you felt something cold against your forehead, someone found you out there and took care of you, but you were still not at the Survey Corps base, meaning you were still outside the Walls. You tried to sit up, but you heard Mikasa's gentle but stern voice as she pushed you back down.
"Stay still. Don't sit up yet. You're injured and have a fever from an infection."