It's the Little Pharmacist

I am a prospective freshman at the Medical University. A few days before the semester started, I followed my sister-in-law who was suspected of cheating on her to a local museum. As a result, I was involved in a time-travel incident? When I woke up, I was only three years old. Then my parents' caravan was intercepted by bandits, and I managed to escape. Wait, why is this so outrageous? A strange couple adopted me, but they insisted that I become their teacher and learn poisoning techniques, but I wanted to be a doctor! This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.