What is happening qualifies as 'experience' because it comes with an implicit metaphysical account of itself. The basis of certainty in this account is not something internal, as say the cogito pretends to be, that is self-certainty, but an appeal to what the other would take it to be. Your certainty relies on your trust in the other's knowingness, and where you are equally apt to play the role of the other for an other. Even the cogito breaks down in this way: its conclusion could be paraphrased as 'See, I am!' It contains a safeguard against subjectivity, but that safeguard doesn't really work, it is nothing but a sleight of hand that you choose to go along with, since the alternative is distressing.