

I try asking why they think that, and try to relate in a way to whatever they answer. I would probably give a realistic advice based on what I heard
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I would probably have the same "conversation" with myself. Trying to analyze myself, learn my mistakes and try to fix them for the future.

I would say the same, and I think, they don't know what they missed :)

Maybe I didn’t try harder. I should try hard.

it wasn't work for you. It means that you will find something better. Now we need to think what you can change or improve to get a job next time.
I will analyze where I made a mistake to do it better next time.

Situation: Your friend had a job interview but the interview did not go well. What do you say to them/what advice do you give when they tell you?
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Now, imagine instead of a friend, YOU were the one who had a bad interview. What would you say to yourself?

I say "don't worry, be happy" . This is not the end of the world, the better job is coming! You will get something better!
Advice- I just ask what do you think that didn't work well? Maybe you can do that better the next time.

Continue to apply for others jobs, you will surely find a better job than that.

No worries, there is always a chance. If you are working hard, there is always reward no matter what.