I currently live that proper state of delusion that allows full placebo effect and toothpaste is not expensive enough to warrant a reality check.
Thankfully, that's not a taste related thing like parent, so I borrow toothpaste from friend, family or hotel the few times I travel. Also, since it is feature based, other brands have started introducing similar feature, allowing me a bit of variation.
But really I can understand parent, I have had a period were I was so scared of going to the dentist (I was 30+ at the time) that I was following a very strict routine religiously. I took my toothpaste, brush, rince and floss on my wedding night. They travelled with me to another continent on my honey moon. I took them to the hospital to use on the night my son was born.
But similar to the previous poster, I (and the people similar to myself) don't have this at all with soap or shampoo.
But soap is soap is soap, and toothpaste is the same ingredients in the same concentration for basically every manufacturer (and even then, it's mostly the mechanical action of brushing that gets your teeth clean, not the toothpaste itself -- you can brush with water in a pinch and still be fine). I convinced my husband to buy generic toothpaste and it's saved us DOLLARS (Woo! Big money!) a year!
The only exception I make is for anti-perspirant (also something I haven't ever seen in hotels) because some brands make my skin become red and fall of and some don't work well enough.
I have never met someone as picky as you say you are with your toothpaste. I don't think you're the norm in any way.