Great post.
I think they HAVE gotten into the habit of thinking that they can just turn it off and on whenever they like.
They’ve gotten into some bad habits all around and need a bit of a reset. If the Bruins spot Toronto or Carolina or anyone else multi-goal leads on a regular basis in the playoffs, their historic run will be over so fast their heads will spin.
The thing about bad habits and bad mindsets in pro athletes is it's usually not self-apparent that they have them. Players don't go around
wanting or accepting of being somehow lazy or deficient, and coaches can tell or show them about this or that, but that will generally still only take you so far along the path of cognition. Really you have to experience it - see it for yourself in game and the results that arise therefrom.
In that sense loses like this are important, as long as the players don't kid themselves too much that they only happened because of sheer lack of effort/desire. They'll see what went wrong, why it went wrong, and what it meant on the scoreboard. They will hurt, even just a little bit, and that will encourage reflection and improvement. So good on the Bruins for their push in the 3rd and making the game close in the end, but coming up short should actually benefit them more in the long run - they can't play their way out of a hole all the time, the can't continue to burn special teams opportunities and get away with it, and so on.
Let's see what sort of response they deliver against Chicago. At the very least I'd expect a much sharper start to the game.