Buffon has lost two European finals with Juve, in 2003 and 2015, but the Italy great will get a third bite at the cherry after the Serie A champions beat Monaco 4-1 on aggregate after a 2-1 win at Juventus Stadium on Wednesday (AEST).
Juve reached the 1998 final after beating the Ligue 1 club before losing to Real Madrid and Los Blancos - 3-0 up over Atletico Madrid in the other semi-final - are likely opponents in Cardiff.
Buffon remains unbeaten from open play in the entire competition this season, but said reaching the final will not mean anything if they do not go on and secure the Bianconeri's third European Cup.
"It was damn difficult, regardless of winning 2-0 in the first leg. If we had come here tonight with an arrogant approach, we would have experienced some very difficult moments," Buffon told Mediaset Premium.
"We still did, but when you've got the right mentality, you can overcome those obstacles.
"We are in the final, but now getting to the final doesn't count for anything.
"I am very happy, because I've got here in good shape and if I wasn't in a big club and with great team-mates, I would never have come back into the Champions League final.
"Two years ago everyone assumed it was my last Champions League final, and I thought that too, but you have to keep believing in your dreams."