Python knowledge base

import pickle
try:
    knowledge = pickle.load(open("knowledge.p", "rb"))
except FileNotFoundError:
    print("Knowledge file not found, creating new")
    knowledge = {}
    pickle.dump(knowledge, open("knowledge.p", "wb"))
    knowledge = pickle.load(open("knowledge.p", "rb"))



def getChoice():
    while True:
        print("Would you like to know somthing or are you going to tell me somthing?")
        choice = input("you: ")
        if choice == 'know':
            print("What would you like to know?")
            return choice
        elif choice == 'tell':
            print("Ok, what are you going to tell me about?")
            return choice
        else:
            print("Im sorry what??")

def getYesNo():
        while True:
            yesNo = input("you: ").lower()
            if yesNo == 'yes':
                return yesNo
            elif yesNo == 'no':
                return yesNo
            else:
                print("Im sorry what??")

def tellMe():
    thing = input("you: ")
    if thing in knowledge:
        definition = knowledge[thing]
        print("I already know what", thing, "is. It's", definition)
        return (thing, definition)
    else:
        print("And what's that?")
        definition = input("you: ")
        return (thing, definition)

def checkTell(thing, definition):
        while True:
            print("So", thing, "is", definition, "right?")
            yesNo = getYesNo()
            if yesNo == 'no':
                print("Then what is", thing, "?")
                definition = input("you: ")
            else:
                print("Ok great")
                return (thing, definition)



while True:
    choice = getChoice()
    if choice == 'tell':
        (thing, definition) = tellMe()
        (thing, definition) = checkTell(thing, definition)
        knowledge.update({thing: definition})
        pickle.dump(knowledge, open("knowledge.p", "wb"))
    elif choice == 'know':
        skip = False
        query = input("you: ")
        if query == 'everything':
            print("Ok here it is!\n", knowledge, '\n')
            skip = True
        if skip == False:
            if query in knowledge:
                result = knowledge[query]
                print("I think that", query, "is", result, "... Am I right?")
                yesNo = getYesNo()
                if yesNo == 'yes':
                    print("Great!")
                if yesNo == 'no':
                    thing = query
                    print("So what is a", thing, "?")
                    definition = input("you: ")
                    (thing, definition) = checkTell(thing, definition)
                    knowledge.update({thing: definition})
                    pickle.dump(knowledge, open("knowledge.p", "wb"))
            else:
                print("Sorry I don't know about", query, "would you like to tell me about it?")
                yesNo = getYesNo()
                if yesNo == 'yes':
                    thing = query
                    print("So what is a", thing, "?")
                    definition = input("you: ")
                    (thing, definition) = checkTell(thing, definition)
                    knowledge.update({thing: definition})
                    pickle.dump(knowledge, open("knowledge.p", "wb"))
                else:
                    print("Maybe later then")