I’m Tone Deaf?

My cousin and I had a small debate yesterday. I told him that whenever I can’t sing whenever  someone is singing with me or if there’s a loud instrument playing along with me. Then he suddenly juped into conclusion that I am probably tone deaf. Tone deafness is generally an inability to distinguish between musical notes. He walk me through a site to test how tone deaf I was and well… uhmm. he’s right because I only got 24% out of 100 and it was so depressing in my part. You see, i have been attending the music session with him and yet, i’m still lacking of skills to distinguish different keys properly. They said that tone deafness is most likely due to lack or musical training or education which somehow make sense to me I shoud probably take some serious musical course somewhere and learn all the important things. I’m sure I will eventually exert my skills and play any of those cool washburn guitars while singing my favorite piece. It would be cool. Well, at the end of the day, my cousin won the debate and I accepted the fact that I am indeed a tone deaf (as of this moment)