wow some of you would want me dead i think. i'm one of those who takes smaller globs of butter, but i ALWAYS wipe the knife before getting more. when i was a kid my mother had to buy me my own little tub because i wouldn't eat anything with butter unless i could physically see that the butter was crumb free. to this day i write "no crumbs" on all my butter, cream cheese, etc.
i will not eat the food unless the butter is completely melted or otherwise evenly distributed. cream cheese is spread in a fairly thin layer as even as possible, and the edges of the bagel are "deburred" of cream cheese.
besides the crumbs in the butter, there is one other thing that you mustn't do. THOU SHALT NOT wipe the leftover goop from your knife on the rim of the tub. that is 10 times more disgusting than mere crumbs. i gag just thinking of it.