ooh i have a pocketknife

pocketknifes are useful tools for getting out of sticky situations. metaphorically, if you say “ooh i have a pocketknife” you mean that you have just thought of a way to get out of a sticky situation. it could also mean that you literally have a pocketknife on hand

example one:

person 1: i don’t want to go to the party because my ex will be there and we planned on going together

person 2: ooh i have a pocketknife! you could come with me to my sister’s preschool graduation!

example 2:

person 1: i need something to cut this rope
person 2: ooh i have a pocketknife!