You do know, don't you, that it is entirely possible to use heroin recreationally and carefully, and not become addicted.

Try checking out the information on CAMH.ca--search for"Do You Know...heroin"
"Not all people who experiment with heroin become
addicted. Some use the drug only on occasion, such as
on weekends, without increasing the dose. With regular
use, however, tolerance develops to the effects of the
drug, and more and more heroin is needed to achieve the
desired effect. Continuous use of increasing amounts of
the drug inevitably leads to physical dependence."

Note the emphasis on the high risk "with regular use".

Of course it's not a casual decision to make, or an uninformed one, but it ain't black magic either.