You’re right! I thought of the typical soda can and, as far as I remember, those tabs are lifted a little so you can get underneath even by just shoving your finger skin in. But just yesterday I tried opening a can of tuna and was surprised not only by how naturally I do the little lift with my finger nails but also by how very difficult it is to open when you don’t use your fingernails.

Genuine question because this might be a design difference between your country and Germany, where I’m from: Can you not lift the tab a little bit with the skin of your finger and then just pull on it? Are they welded onto the can?