Why won't my project work when oriented a specific way

This is a random username generator. The problem is with the themes list. themes is clearly defined themes = ["Possum", "Pirate", "Plant"]

if request.lower() not in themes: If this line of code and its subsequent nested lines are above this line:

if request.lower() == ("possum"):

The terminal reads:

name's name generator v1

Enter a theme: **pirate**

**That is not a supported theme in this version**

Would you like a list of currently supported themes? yes

['Possum', 'Pirate', 'Plant']

Enter a theme: **plant**

**That is not a supported theme in this version**

Would you like a list of currently supported themes?

It's looping, but this doesn't really make sense to me because if I place:

if request.lower() not in ["possum", "pirate", "plant"]: instead of if request.lower() not in themes:

Writing the list out. It works perfectly when sequenced :

 request = input("Enter a theme: ")

    if request == "q":
        quit()
    if request.lower() not in ["possum", "pirate", "plant"]:
          blah blah blah
    if request.lower() == ("possum"):
        blah blah blah

Here is the completed working code. I changed it to an elif and moved it to the bottom of my script.

import random

usernameposs = ["possum", "poss","oposs", "opossum"] 
usernamepirate = ["pirate", "cap'n", "deckhand", "floor-swabber"]
usernameplant = ["plant", "shroom", "succulent", "garden"]

surname = ["man", "guy", "lord", "vanheel", "fungicide", "beard", ]

themes = ["Possum", "Pirate", "Plant"]


print("name's name generator v1")

while True:
    random_number = random.randint(0, 3) #number of firstnames
    random_number2 = random.randint(0,5) #number of surnames
    request = input("Enter a theme: ")
    if request == "q":
        quit()         
    if request.lower() == ("possum"):
        print(usernameposs[random_number], surname[random_number2])
        request = input("Would you like to generate another username? ")
        if request.lower() == "yes":
            continue 
        else:
            quit()
    elif request.lower() == ("pirate"):
        print(usernamepirate[random_number], surname[random_number2])
        request = input("Would you like to generate another username? ")
        if request.lower() == "yes":
            continue
        else:
            quit()
    elif request.lower() == ("plant"):
        print(usernameplant[random_number], surname[random_number2])
        request = input("Would you like to generate another username? ")
        if request.lower() == "yes":
            continue

    elif request.lower() not in themes:
        print("That is not a supported theme in this version" )
        supp_theme = input("Would you like a list of currently supported themes? ")
        if supp_theme.lower() == "yes":
            print(themes)
            continue
        elif supp_theme.lower() == "no":
            print("Okay, you can enter q to quit")
            continue 
        elif supp_theme.lower() == "q":
            quit()
        else:
            print("stop trying to break it!:)")
    else:
        quit()
        

Why does it work with when I type the list out, but not when I call the defined above themes? And why does calling themes work when I place the whole if statement as an elif at the bottom of the script?

source https://stackoverflow.com/questions/70687849/why-wont-my-project-work-when-oriented-a-specific-way