needs vs wants

who can differentiate between what they need and want?!i can't!!and even if someone can,are they able to live relying only on what their needs?!
one day, a teacher of mine regarding on this topic, asked us class "do you need a cellphone?!"
hell yeah I do!!!!i need my iphone!!what if i get kidnapped?!how can i call the police when there's robbery?!what if someone next to me collapsed?!how can i call an ambulance?!
and then he asked us "what about the internet on your cellphone,do you need it?!"
of course we do!!there's many thing that i don't understand.,and what do i do?!boom!!!google it up!!lol!!and i'm far away from my boyfriend!I don't want to pay trillion yen over roaming!!coz me and him.,we talk a lot!!hell no!!!
and the he said to us "you won't die without a cellphone"
oh no!!!oh nononono!!i'll fucking die without my baby here!!
okay so~even if others won't die without their phone (which i will surely)
are they prohibited of having a phone?!no!!they aren't!
okey so~i have food,water and shelter.,i have all the needs!and what happen if someone has fulfilled it?!
they will buy what they want!!there is no millionaire who only buys food and water!!no!!
and if everybody only buys what they need,the flowing of the money will go bad,economic crisis happens that will worsen the climate change and lead to a world disaster and eventually end of the world as we know!!so if you don't want the world to end,buy things that you want!after having what you need of course!!this topic sucks!!lol