Mourinho, who was 51 on Sunday, marked the occasion by sharing some champagne with the media ahead of Wednesday's match against West Ham at Stamford Bridge.
When asked if he reckons he will be celebrating a Premier League success with further champagne at the end of the season, Mourinho insisted his squad was still developing.
"I don't think so," Mourinho said. "I think we have to drink champagne because we are improving. I think we are improving a lot. The team and the players, so the perspectives of champagne in the future are good. I think we are going in a good direction.
"We are playing well. I think we are playing well. I think the game against Stoke was a good 1-0. Quality. Individually, very good performances. Collectively, very good. The quality of the game was good.
"Defending well is also an art, and they defended very well. So I think the team is playing well.
"You never know what is going to happen in the next match, but the reality is that the results are arriving as a consequence of the team playing very good football."
Mourinho is pleased with Chelsea's transfer business this month, which has included Manchester United paying £37million for Juan Mata and Kevin De Bruyne's £17million move to Wolfsburg, while the Blues have secured Mohamed Salah from Basel for £11million.
"We are happy with what we did. The Kevin De Bruyne (move) was expected," Mourinho added.
"He's a fantastic player but was an expected deal for us, and very good if you compare what Chelsea paid for Kevin a couple of years ago and the amount we made now.
"Juan was unexpected, and we answer immediately with Salah which we believe a 21-year-old boy in his time will be a good player for us."