what must it be like to be always happy?

Great weather this weekend, bright, cool and sunny! There was this community matsuri (fair) for kids where I won at the raffle.
I also saw in person this woman who was featured on TV one time. She's in her late 30s and years ago she had an accident while riding her bike. She hit her head on the curb and that damaged one part of her brain, the one that makes us recognize sadness. So now she does not get sad at all, no matter what. She feels no worry, nor grief. She is always happy and has no concept at all of what sadness feels like!

Doctors have given her a choice that she could either live that way or they can try to at least "repair" a damaged part of her brain and that it might make her recognize grief. So far she has chosen to stay "happy" because she does not know what that change would bring her. If you saw her on TV, she always had this permanent smile on her face and her reaction to almost anything was always a happy one. One time she got lost, due to a memory lapse, instead of worrying, she just laughed at her predicament.

I saw her today at the fair, in the flesh. She looked like everyone else unless you knew about her condition. She does wear that smile all the time, the only person I know who is 100% HAPPY.