I have needle phobia. I can get whoozy just thinking about being poked by a needle. And blood - I cannot look at it without likewise getting lightheaded. I've been that way since I was 'knee-high to a grasshopper'. I might have been a medical doctor if ... No check that, I am an engineer because I love the rush of creating.
There is an indescribable emotional rush from creating a new product. It might have a few bugs, but you stand back in amazement when it works. If you remember in Back to the Future, Doc Brown first meets Marty wearing a metal colander on his head. When he incorrectly guesses what Marty has come to see him about, he exclaims, "You know what this means - this *#*@ thing doesn't work at all!"
After completing my first novel - see the page marked "Roman DNA", I also experienced the same rush when I breezed back through the book. 'I created a character like that?' and 'wow, that really fits together neatly,' are similar experiences to product design. However, I digress...
According to Why Does Blood Make Some People Squeamish But Not Others? , fainting at the sight of blood is because of an overactive vasovagal response. The article goes on to say that it becomes less intense after continued exposure to blood. So buck up, bucko! Maybe if I had worked at a butcher shop as a teenager, I could have been something else. But no, my calling was to create, just as an actor's calling is to perform on the stage.