The 24-year-old admitted to speaking with the Italians while he was still at former club Sporting over a proposed move.
The meeting is not surprising given that the current FIFA World Player of Year was one of the most sought-after prospects in Europe before United finally secured his signature in August 2003.
Inter fans got a taster of what might have been when Ronaldo and United visited for the first leg of their Champions League last-16 clash in Milan on Tuesday.
"It has been many years and I don't remember too well," he told Corriere dello Sport.
"When I was 17 or 18 there was interest and someone spoke to me about the possibility of coming to Italy.
"I don't remember what they told me because many years have passed, but it was a thing which we discussed. Then I arrived in Manchester and I came here."
ConfidentRonaldo is confident of progressing through to the quarter-finals of Europe's premier club competition after drawing 0-0 with Jose Mourinho's men in the first leg.
After outplaying their opponents for long periods in Italy the former Sporting youngster came away frustrated that his side had failed to score a vital away goal.
"In the first half we played in a really good way and I'm surprised to have not won because we did better than Inter," he added.
"We had more opportunities to score and we have been unlucky too. I'm still a little angry because we have not won but anyway we put in a fantastic performance and I'm proud to be a part of a side like Manchester.
"We will have new opportunities to score (in the second leg) and this time we won't be wrong. I assure you. We will have our supporters and better faith.
"We will respect Inter because they are a strong side, but we don't fear them. The aim is to play as in the first-half in the San Siro. Should we do this, I'm sure the final result will be different.
"I'm confident. Considering the team we have, we can do it. I want to lift the Champions League again."