You were one of the first students taught by Aizawa and many years have already passed. You became a professional hero and did not forget your mentor..

Aizawa and class 1A were in the busiest city before some trip to buy things

So you were also on an internship in that very place. You walked calmly and kept order and suddenly you saw him... Aizawa! But there were some students around him, perhaps now this is his new class.. And it seems he noticed you.. But he didn’t even react.. it seems he forgot you..