The Blues currently sit third in the table with 24 points from their first 12 matches, but have already tasted defeat away to Everton and Newcastle this season.
And Mourinho feels the increased competition of England's top flight this season means finishing top would be even more impressive.
“Winning the title this year would be a greater achievement than before, yes, I think so,” he told reporters.
|18/5||Chelsea are 18/5 with BetVictor to win the title this season|
“But winning the title this season would be a really good achievement, yes.
“I think the competition is different, the teams are different. In my first time it was just three teams fighting for the title.
“Now we are six and the difference between the three and rest was a big distance, while in this moment the distance between the six is short. And the distance between the six and the next three or four is also short.
“This is difficult. Nobody knows what can happen. Maybe the difference between succeeding and not, or reaching Champions League or the Europa League, or the Europa League and nothing, is a couple of points.
“But it will be really good fun. We have the competition that every country wants to have and nobody else has, not Spain, Germany, Portugal.
“Here we have this fantastic league, so we shouldn’t complain. We should enjoy it.
“If you’re asking me if I’d prefer to be top of the league and the second to come 10 points off me, I’d love it.
“But I love the fact you win a match you’re second, you lose you go from second to six. Lost two you’re out of the European places. I think the league is fantastic.”
Chelsea have dropped five points in November after an away defeat to Newcastle and a home draw with West Brom, but Mourinho insists all the title challengers will endure blips.
“In this league, if to lose two matches is to be under pressure, then I think everybody during the season will be under pressure,” he added.
“Everybody will lose two matches, or lose one and win then lose again, or draw, win, lose. It’ll happen to every one of us.
“So these situations of five, six or seven consecutive victories? No. Everyone has to understand how it is. I did 100 points with Real Madrid. In the Premier League, that won’t happen.
“I don’t know how many points will be needed. But I’d say maybe a team with six defeats can win.
“If I forget the performance from the last match, our situation is fine, we are okay. But we have improve stability in our game, we have to improve aspects. Of course we have to.”