The former Italy international won two FA Cups, one Charity Shield, one League Cup, a UEFA Cup Winners' Cup and the UEFA Super Cup with Chelsea as well as a UEFA Cup and UEFA Super Cup with Parma and the Serie A title with Napoli during his playing days.
On Monday he has the Hornets in the playoff final where they will meet Crystal Palace at Wembley and he suggests that guiding them into England's top flight would be his best achievement yet.
"As a footballer, you feel you played at different venues in important games, and you think that you lived all the experiences in football, the good and bad ones, but as a manager it amplifies everything - that is what happened to me against Leicester, I went back 20 years. Fortunately for me it was a good feeling, and that was great," said Zola.
"I have been blessed to have enjoyed a fantastic career, with some very good moments, but to win this one would have it rated as one of the best because of everything you go through as a manager. You take in every player's emotion, positive and not positive so you live everything.
"Winning this game will be one of the most important (of my) achievements.
"As a manager, everything is multiplied, so if it happens, then it is going to be amazing and I am sure I will celebrate the same way I celebrated when we won the first FA Cup with Chelsea at Wembley."