Heynckes joined Ernst Happel, Ottmar Hitzfeld and Jose Mourinho with two Champions League trophies from two clubs after Bayern beat German rivals Borussia Dortmund 2-1 to add to his 1998 European crown with Real Madrid.
With former Barcelona coach Pep Guardiola taking over next season, Heynckes led the Bavarians to two titles, after also winning the German league, and could add another with the domestic Cup next week for an unprecedented treble by a German team.
"It is unusual the way we played football this season," Heynckes, who also won the World Cup and European Championship with Germany as a player in a career in football spanning half a century, told reporters.
"No one could have expected that. My career was pretty much over four years ago," said Heynckes, who also coached Bayern in the late 1980s and won two league titles with them and again took over for five games in 2009 following the sacking of Jurgen Klinsmann.
"Then I had a couple of good years in Leverkusen with a first-class team and now since last year we've improved continually here."
"We improved a lot of things, modified a lot of things. The product we have is a team spirit like never before. The players understand each other brilliantly," he said.
"Maybe I was a little more strict, more concentrated in the details this year than ever before," he said.
"With the assistants we changed some of our work and it was decisive that the players came with us 100 percent and the harmony was there."
"It's important that the players kept up their high spirits. It's important because some players are on the bench and don't get into the squad," Heynckes said.
Bayern's success has seen offers pour in for Heynckes who has already announced his retirement from the Bundesliga.
"I decided what I would do last summer after the Champions League final defeat," he said. "On June 2 you will find out what it is."
