Can you recollect this number- 123

Be honest and please do not guess for the question asked next. Now hide the number with your hand and read along.

Do not try to recollect the number but try to answer the next question with a yes/no. Do you remember the number you read a while ago?

Yes ofcourse. You can take your hand off the screen now.

Let me explain to you what just happened. You read that number with your eyes (translated to electro-chemical signals and sent to your brain did some image processing and identified it as 123) and then your mind stored the number in your brain, in a form that it can read. Then you tried to answer the question.

But how do you know if you know that number? This is a very complex question. Please let me tell you that you just did not answer that question honestly. You just guessed.

If you did not try to recollect the number but just tried to know if you could recollect the number then you just had a feeling (with a lot of confidence) that you could recollect this number.