Neil Lennon admits Celtic's European exit is the only black mark on his side's 2020 form book.
The Hoops ended last year with defeat to Rangers but since then have been almost perfect domestically.
Eleven wins and one draw from their 12 Ladbrokes Premiership fixtures helped the Lurgan man's team establish a commanding 13-point lead at the top of the table before the coronavirus crisis forced Scottish football into lockdown.
They carried on that merciless run as they marched into the last four of the Scottish Cup.
However, there was Europa League disappointment in the last 32 when Celtic suffered a surprise defeat at home to Copenhagen.
Reflecting on Celtic's form since returning from a winter break in Dubai, Lennon said: "What's pleased me has been the quality of our performances - even if you look at our last game against St Mirren when we beat them 5-0.
"To do that at this stage of the season is pretty impressive because we were struggling to score goals this time last year, so the amount of goals we've scored and the amount of wins we've racked up is impressive.
"And since the turn of the year, to go unbeaten domestically and only drop two points is fantastic, and we reached the semi-final of the Scottish Cup - we've already won the League Cup - so it just shows how well we've played.
"It's been pretty impressive, to say the least, from the players and I'm so proud of them.
"The only disappointment to me, really, was going out of Europe the way we did. That was really disappointing because we really felt we could make inroads into the competition."
Celtic have tallied up 10 points more than they managed at the 30-game mark last term, while they have scored an incredible 141 competitive goals across all competitions so far this season.
Lennon added: "That's absolutely brilliant and it's what we were looking for - myself, John Kennedy, Damien Duff and Stevie Woods - as a backroom team. We knew there were more goals in them. We train that way, to be positive and on the front foot.
"Our record for 2020 would stand up to any club in Europe or even throughout the world, and it's not the easiest thing to do because teams are set up to stop you scoring or try to nullify you in any way they can, so I can't ask any more of the players.
"The mindset has been good as well. It's how I want to see Celtic playing. We're there to entertain the fans, and that's in the DNA of the club, so the players have responded in the right way, there's no question."