What's the difference between wimpiness and real sickness?

I'm not a good sick person. In fact, I might even be a bit of a hypochondriac. Nonetheless, I'm pretty wimpy when it comes to pain or discomfort. I do, however, have one surefire tell to know difference between true sickness and wimpiness... I don't sing along with the music that's playing.

You can ask my husband; I sing all the time. If I hear just a small bit of a song, it's instantly in my head. If I'm not singing, there's something wrong with me.

I haven't sang much the last few days.

I'm curious, what's your tell?