Know How People Tell You To Get A Plant First....

Ever heard someone say you should be able to have a plant and keep it alive before you get a pet, relationship, do something drastic? I can't!
I have tried to keep multiple plants alive and it is impossible! It isn't that I forget to water them, or even that I water them too much. I have sun in my place, TONS of it. It's a stable temperature inside, and when it's warm enough I take the plants outside. My plants will live for about 6 weeks; they will seem in perfect shape. Then I will wake up one day and they will be dead. I have NO clue why this happens or how!
I am glad I have not taken the advice to heart I have two cats ages 1 and 2 and they have been alive and healthy the whole time I have owned them. Last summer I worked as a full time nanny for an infant and she is alive and well too. I think this saying makes sense for someone who forgets to brush their own teeth or can't get up on time maybe. But I am a put together person, and I can't keep plants alive!
I would be more likely to agree to watch someone’s baby for a month than water their plants for 2 weeks because I know I would kill the poor plant. It's funny how that works. Maybe I need more to do with something than just watering it and making sure it has proper light? Who knows I am just saying that phrase should probably be tossed out!