According to this book (page 1052, right column, 3rd paragraph), some understand their bladder is full through self-palpation (feeling for it from the outside of the abdomen). Has anybody had any success with this? Where did you learn it? With us, during a UTI a small amount of fullness can be detected due to pain when tapping, but no such sensation normally, so we are interested if we can feel for the size of the bladder. Presumably it would require some anatomy or an unusual amount of self-knowledge.
I can tell when I'm full, as my legs seem to wander off in different directions, the tapping is useful to trigger a release when I want to go without cathing - but doesn't always get everything out first time . .