Robin's on drugs + hallucinating. When did all begin?

I take the view that she begins when she takes that sniff right when she is on the road and has that chat with the tollbooth officer. The officer gives a hint that Robin Wright will see him only twice - once when she meets him just before the animated world, and when she leaves (he is shown behind the counter just before Robin comes back to reality). Also, when she goes back to the "dream world", she is looking though the perspective of her son, and I think the last time her son sees her is when she is taking the car drive to enter the animated world.

I for one didn't interpret it that way.

We don't know a whole lot about how she spent those twenty years between signing the contract and showing up at the Abrahama gatehouse. We do know she didn't play golf (she doesn't like it). We do know she was moderately well off (it's implied the contract paid very well, and she drives an expensive car). We do know she aged gracefully (she looks quite healthy in the car).

And we can surmise this is her first experience with the not-so-real world, partly because that's what she tells the guard, and partly by her reactions (she wouldn't describe her reflection as "..... on a bad hair day" if she'd already been inside for those twenty years).

The twenty-year period of the contract was followed by another twenty-years in suspended animation after being injured in the rebellion at Abrahama, waiting until medical technology could cure her. The nineteen years Aaron waited started at the time she drove to Abrahama.

if anything, i'm thinking that her trip to the "Real world" after taking Jon Hamm's pill is the extension of her dream. The doctor she's looking for is on the first derigible she boards? She's able to recreate her son's drug trip and find him? She gets the reaffirmation of her opinion that the drug-world is bad and the real world is "the truth" from the ENT doctor?

It's all very "wish fulfillment", isn't it?

But who knows? Films like this are always more of an emotional experience than a logical one.

According to Ari Folman everything that is animated is an hallucination.