Never quite got over it since back in the early 90's when I was doing my first apprenticeship. I spent 3 months in the fab shop at a structural steel manufacturer. Anyway I had the job one day of stamping all the codes on the steelwork so you knew where it would go. Been doing it all morning until full swing missed and exploded my thumb.
Now hammering nails no phobia but as soon as I pick a letter/number stamp a different matter. To this day I get a bit of chill when I first swing the hammer on the first stamp.