How much good is the Celtics’ feel-good vibe?

Greg M. Cooper-USA TODAY Sports No, really. Things weren’t THAT bad last year. But we’re just having SO much fun this year.

That’s not a direct quote, just the general vibe I’m getting from all the early comments in camp thus far. We knew that this was coming. The team needed a change of personality and they got it. Out with the old, in with the refreshing and new. It doesn’t even seem forced. These guys genuinely seem more relaxed and focused on bonding as a unit.

When players lifted weights before the opening practice Tuesday, they did so in groups, rather than on their own as was typical last season. When they shot around on the court, they did so with other teammates. The changes aren’t…