Sum up a sim's traits in one quote...

You are correct! 😁

It turned out to be Self-Absorbed, EgonVM XD

Traits?  I have traits?  But we're all so alike.

Okay, here's another.

"I haven't played many gigs but I can assure you, all of my imaginary friends thought I was amazing."

I'll try this one:  Music Lover, Loner, and Self-Absorbed.

Almost! Two of those are correct.

(Did you mean Self-Assured or is there a Self-Absorbed trait too? I don't own all of the packs so I wasn't sure). 

There's a Self-Absorbed trait; it's a Social trait that was added with Get Famous (I think).  

Hmm...now I'm thinking I was right about Music Lover and Loner, and that your Sim is Self-Assured, not Self-Absorbed.  🙂