Interesting you mention up to December. That is when the cracks appeared. From memory, we started dropping more points and went into the 29th on the back of some indifferent performances and results. To the point FF was toxic in the lead up and very few on here were confident going into the game, stating the league was done etc if we lost it.
Difference is we had a run of tough away fixtures preceding it, this season we've played them already and only dropped 4 points on the road, 2 of them unjustly due to an offside equaliser. We have beaten Celtic convincingly, gained a lead and haven't gifted it straight back as we have been prone to doing the previous 2 seasons. We now also have the run of tougher teams at home and the 'easier' away games whilst they have all the tougher away games. During the equivalent fixtures last season we only lost once, at home to them.
During the first quarter alone we've lost Katic for the season with Barisic, Helander, Jack, Aribo, Roofe, Itten, Defoe, Barker and McGregor all missing for various periods due to injury and barely been affected by it. We are conceding far fewer chances, any individual mistakes are not being as harshly punished (luck does play a part in title wins) and all areas of the pitch are contributing goals or assists instead of an over reliance on morelos to be on his game, or simply just available, as we were last year.
I see so much improvement in our team, squad, game management, rotation, tactics and overall play this year, combined with the regression in theirs, that I can't help but feel over excited. I salute and envy your ability to remain calm.