Some are brainwashed. Some are fully on board, without any need for brainwashing.

Most are on the path of least resistance, not asking many questions as long as life is ~comfortable, or at least not getting dramatically worse. They kind of like the strongman. And there is always alcohol/drugs.

Added: In general I agree with varjag's assessment. The average Russian family supports Putin.

Summed up nicely. But now they will get some sobering up.

I have little faith that Russian society is going to come out of this war any better. It's a cultural thing. Germany had to be razed to the ground by am external force and millions of Germans had to be killed for the society to ditch militarism. And Russia has nukes.

Yeah exactly. You're the only one inmune to propaganda, it's everyone else who is brainwashed. It obviously couldn't happen to you since you're smart, and "normal Russian people" aren't.

I guess the question comes down to who is responsible for one's own sanity. The individual, the community, or the state? Anyways, I would argue that attributing Putin's popularity to brainwashing is not that solid of a theory. Perhaps Putin is popular because Russians want a strong leader in the wake of previous leader who were seen as weak.

We can't know without better introspection and data to ground the discussion.