Can food go down into your lung unnoticable? i ate oats and needed to sneeze, so when i took a deep breath, it felt like one went down. no symptoms.

Not likely: It would take a very small amount to go into your lungs with no symptoms. Thinks that go into your airway are very irritating and your body does its best to cough them out. So it's unlikely this happened to you. It does happen sometimes in people who have had significant strokes, as their ability to protect their airways may be diminished by the damage the stroke caused.