It's very soothing to sort through a box of stamps, dividing them by the colour of the paper they stick to, soaking them off paper in tepid tap water, drying them under paper towels, pressing them in your cute plastic stamp press, sorting them by country or topic, watching for varieties, putting them in stockbooks, deciding to make an exhibit for the next club meeting, mounting them on pages, researching the story your exhibit will tell, winning a gold ribbon....
All without having to talk to anyone, or work the way someone else wants you to, or use the products that are "the only right way".
It's a hobby.
You can do what you dang well like.
A normie version of stimming. Even more so for those who are not neurotypical.
