Atletico Madrid and Barcelona will face off for the trophy at Camp Nou on Saturday after Real were ruled out of the running in a 2-0 defeat at Celta Vigo on Sunday.
And Ramos admitted the outcome left him feeling dejected, but stressed the focus would now turn to a UEFA Champions League final meeting with city rivals Atleti in Lisbon on May 24.
"You go home feeling sad and disappointed for having let this unique opportunity to win the title pass us by," he said. "You realise that the Spanish Liga is the best in the world because any team can beat you. Nobody would have expected Barcelona and Atletico not to win (on Sunday).
"Now it's time to think about the Champions League final and be self-critical. In other seasons winning the Copa would make it a great season and we won it this year.
"We have given our all on the field and tried to play as well as possible. We shouldn't take anything away from this season.
"That's football: one day you're up, the next you're down. Madrid is capable of anything. We have to reflect and draw conclusions.
"The team has had injuries and over the season it has affected us."
