Last year, I was in a couple of classes with a guy from uni. Him and I worked together on a project for a couple of months in a team. I also chatted with him over whatsapp and in person quite often. I bumped into him a few weeks ago and I asked him how he was. He looked at me blankly. He really did not seem to even know who I was. I tried reminding him about when we worked together on that project, but he said I must have confused him with someone else. I have definitely not confused him with someone else. Anyone got a clue as to why he said he does not remember me?