How is the feeling of being a failure?

How is the feeling of being a failure?
Today after the class ended at 6pm I can see the sorrow on my roommate's face.
He's totally down. He said he did badly in the presentation. He said he could hardly finish what he had planned. He was stuck,bad pronunciation together with the tense made him feel totally not him. and at last he told me he's a FAILURE.
Failure?How do we define failure?

Honestly i have had this kind of feeling,when I couldn't reach my target,when everything goes oppositely to the way I want it to be.
I could still remember when i was in primary school,my mum had a high demand on me.
I had been inculcated,taught and guided to be the top student in school.
She taught me,checked my homeworks and even set mock exam questions for me .
I could still remember it was once where she gave me math questions and told me one cane for every single mistake that i made.I was really stunned where I wailed while I finished up the questions. And it turned out to be I made quite a number of careless mistakes and was caned by her. She stop guiding me after i entered year 4 and soon after that until I sat for my UPSR,PMR and SPM .
I never blame her for being so stringent to me when I was first few years in primary school.
Instead I would like to thank her,for builiding such a strong foundation in me when I was small.

I always set high target on myself. I know everyone can achive the non-achievable by working hard. Yet reality is cruel. Nothing will go on smoothly. Sometimes one needs to resign oneself to fate. Maybe luck just doesn't with you at the particular time.
I did have some failure experience..I would be very very sad,then I will keep asking myself 'why could't I do that?' ,'how can I not able to do that?' ,'what's wrong?' etc etc etc..
the sadness,the pain of being a failure will remain in my mind until i manage to concur it,manage to solve it,manage to say 'hooray I did that finally!'
I think the sadness or the feeling of being a failure somehow drive me to work harder.It reminds me how I fail,and how I not wanting to repeat the same error,same mistake again,just as the chinese saying,'failure is the mother of success'. Without failure no one can ever succeed.

So to my roommate,I know it's really taxing to think yourself a failure. I hope this will help u regain your confidence and ace it next time!
as for myself,I will persevere and hope I can do well!