Encounter with one who lacks EQ can make one vomit blood

Yesterday evening, I took B.'s vehicle home together with another gal. To be very blunt, a rich brag. One who's lacking in EQ in my opinion. As usual, everyone seemed to be very interested in what I'm doing... which is fine... which I'm quite happy to share (but really, how much can I share without making it overly technical?). But this fellow kept diverting to monetary benefits and stuff... "How much is the fees? How much are you paid? How much are the rest paid?..."
It's not a secret but I'm not comfy with the way she asked and naturally, I chose not to divulge... and that was met with a "Why?" which quite shocked me! And if all these aren't enough, she continue her quest to question if I'm really interested in what I'm doing even after I explained to her why I chose to do this project (and this was already done close to the start of the conversation).
*Puzzled* ... *Faint*
Haiz, seriously, I really have nothing much to say... I just don't feel like talking.

Hmm... I'm just pondering... not that I've very high EQ... but...
Do you, on your first day of work, go around asking your colleagues how much they are paid or what benefits they are getting?
Do you, upon knowing someone within less than 20mins, asked him/her how much he/she is earning after you know what he/she is working as?
Do you, upon being rejected by that someone who refuses to divulge his/her pay scale, follow up with a Why-cannot-let-u-know-kind-of-question?

Were we taught these? I don't think so... Usually if you know that person well, then don't say lah... but to a complete stranger that you barely know?

My question is: Do we really need to be taught such things?