Not every person who uses a particular drug recreationally can or will get addicted to it. It depends on brain chemistry and a variety of other factors.

Nope. Do heroin 4 days in a row and you start having withdrawal symptoms. Regardless of any other factors including brain chemistry.

As far as noticable withdrawals, it takes a lot longer than 4 days for someone who’s new to it. If you’ve ever been an addict to opiates before though, yeah that’s about right.

Most recreational use doesn't constitute such things, though. Unless you have a very different view of recreational use than I do.

That's true broadly, but opiates are a bit of a special case, no?

If they were immediately addictive, everyone that got a morphine shot in the hospital would need to seek treatment. It isn't a "one use and you are addicted" or even "occasional (recreational) use will get you addicted". A portion of folks will seek it out more often, but most folks will just seek it out occasionally.

With opiates, the bigger danger is daily or consistent use over a period of time. The period depending on how often you take it and how you are using it and the strength of your dose.

Yes, but it is the same with things like alcohol. Most folks that smoke pot daily don't start out that way either. Most folks that wind up with a coke habit only do it occasionally at first as well. Lots more people do these things in an actual recreational pattern - every so often. Only a portion get addicted because only a portion ever do it that often.

Yet, if someone has an incident with alcohol (for example), they might be required to attend AA meetings even if they aren't a regular drinker. Same with other drugs.

This is true even if heroin withdrawal symptoms start after just a few days. Recreational use generally isn't daily use or two days in a row.