First impressions matter!

How do you feel twhen you hear the "tell me about yourself" question?

Since it is a specific question that we are supposed to know, "the" is needed.

You could also word it this way:

How do you feel when you hear the question, "tell me about yourself"?

Of course , of course, the question is wrong; and the interviewer shwould do better to be more open and direct, and actually ask, “What specifically about you meets my needs ?”.

Does not matter , we all are all seasoned professionals here and know this trick perfectly.

The pProfessor Rebecca Okamoto , a Communication consulter, shows us a very good example of how to do it when presenting onin her/a TEDTalk.:

If she has only given one talk, then "in her TEDTalk."
If she has given more, then "in a TEDTalk" and you could add the date or the location to specify which one.
A colon shows that the next part is what she said.

Tell me twhat you can do for me in only 20 words.

(Can you imagine trying to count up to 20 words as you formulated your answer? I can see this as a written prompt, but it would very challenging in a live interview.)

Then she shows 5five main topics to choose from/refer to, like help, mission, strength and others to choose from .

It's not really clear how the set up works. I think I understand that the person supposed to incorporate a certain number of these topics in his/her answer?

And she is bright!

This could sound a little insulting to say about a professor.

Exactly as everybody wants to sound when they answers.¶
Exactly as we all want to sound when we answer.

Some style guides will allow the plural "they/their" to refer to "Everybody" or "Everyone" because it is done a lot in spoken language and it is a real problem to have to write he or she, he/she, or s/he, his/hers etc.
HOWEVER, some style guides will never accept this as correct, so I offer you an alternative that would work.

Suddenly, I blink and, and the magic clears away, s. Something breaks.

There are different options for punctuating this, but the comma before "and the magic" is a must.

Nothing real, only words.

You may be repeating "only" in these two sentences for effect. That's cool.
But if you didn't intend to repeat that word for emphasis, then you could replace one "only" with "just."

That is why, very often, corporates end up withions hire people who knowing how to talk, not to how to do the job,: they master the faire-savoir instead of the savoir-faire.

"end up with" is fine, but I think "hire" points to the seriousness of the problem.

I will also be [heaving] the 20 words speaech in my pocket but just to open me the way to a real achievements for myself.

"heaving" doesn't make sense here because we use it for things that are very heavy. It might be a typo for "having" but that doesn't work grammatically. Based on what I think you mean, I would suggest "carrying" or perhaps "packing"

"a real achievement" or "real achievements" not sure which you intended