Good for you!
I on the other hand, believe I am very bad at singing because what I hear when I sing is horrible. I have fairly good (if untrained) musical hearing and love listening to others sing, so I think it's likely I'm right about myself.
My parents have indeed always told me I sound horrible and have no musical talent and must never sing. But I think their actual influence was mostly in convincing me not to try to learn/practice to sing.
what I hear when I sing
can be somewhat different from what others hear. Try recording yourself and listening back. (Though for some reason most people hate that, at least with non-singing speech -- I think I once read about some study about that on Language Log.)
ETA: More anecdotal evidence that people might underestimate how good they are at singing:
A couple weeks ago I was in the bar where I usually sing karaoke on Mondays, and a girl (whom I knew by sight because her boyfriend studies in the same university department as me, but with whom I had neve...
The other day, someone did something I didn't expect. It was something many people have done before; something that I thought of as very normal, but that I in no way understood and had not predicted.
As I said, this had happened many time before, so I wrote it off as "me not understanding people" or "people are weird" for a second, like I usually do, before realizing that "bad at" really means "lacking basic knowledge", which I had never realized before.
And then I thought "I should ask someone who is different from me why people do that, and eventually someone will have an answer."
But many people will have many more questions like this. So, what have you observed people doing time and time again, but never understood? Or something that you only understood after a long time or asking someone about it?
And can Less Wrong tell us, not necessarily why (I for one can make up evolutionary psychology fairy tales all day if I want) but what conscious thought process occurs behind these events?