"I have a black thumb. I kill everything." It is the most common thing people say about houseplants, and it is almost always false. There is no mystical green-thumb gene that some people have and others lack. There is a single, extremely common habit that kills the majority of houseplants, and the cruel irony is that it comes from caring too much, not too little. You are not bad with plants. You are overwatering them.
Why love drowns plants
A houseplant in trouble looks sad, and the caring owner's instinct is to do something — and the easiest something is to water it. So a drooping plant gets watered, then watered again, and the constant wet suffocates the roots, which need air as well as water. Roots sitting in perpetually soggy soil rot, the plant declines further, the worried owner waters more, and the plant dies of kindness. Most "I killed it" stories are this loop: a plant loved to death by a watering can.
The black-thumb myth is doing harm
Believing you are simply bad with plants is a self-fulfilling excuse: it tells you the problem is an unchangeable trait rather than a fixable habit, so you stop trying or keep repeating the same mistake. But the skill is learnable and the main lesson is mostly about restraint — doing less, not more. Once you reframe "I have a black thumb" as "I water too often," the whole thing becomes solvable.
The takeaway
Start by watering less and checking the soil first. Choose a forgiving plant, let it dry between drinks, and resist the urge to fuss every time it looks slightly off. You will keep things alive that you were sure you would kill, and you will discover the green thumb was never a gift you lacked — just a watering habit you needed to break. Care for plants by holding the watering can less, not more.