The Swedish striker wrapped up proceedings for the Red Devils with a superb strike from more than 20 yards in Sunday's 3-1 victory over AFC Bournemouth at the Vitality Stadium.
Regarding the summer signing, Mourinho feels that despite his ageing years, Ibrahimovic can still be a force both on and off the pitch for United.
"The first thing I can tell you is that his table for breakfast and his table for meals, he is surrounded by the young ones, surrounded by the kids," said Mourinho.
"Luke Shaw, Marcus Rashford, these are the guys that are with him on the table. So he knows what he can be for them.
"But for the team, you have to forget the passport, you have to forget 34 years old, because the body and the mentality is not of a 34-year-old guy.
"So I think he's at the top of his qualities."
Juan Mata scored United's opener on 40 minutes before Wayne Rooney added a second just before the hour-mark.
On 64 minutes, Ibrahimovic found time and space outside the area before striking a perfectly placed effort beyond Artur Boruc prior to Adam Smith's quality reply for the Cherries with 20 minutes left.