Few expected Jurgen Klopp’s side to enjoy such a European adventure in 2017-18, especially as their continental campaign had started at the play-off stage.
There was to be no fairytale ending, as Real lifted a famous trophy for the third year in succession, but Liverpool had shown what was possible.
Positivity has carried over into the current campaign, with seven straight victories helping the Reds to generate a fear factor that has them chasing down major honours and rivals running scared.
Former striker Aldridge told the Irish Independent: "There is a visible change of mentality in Jurgen Klopp’s Liverpool team this season and it's not just down to key signings they have made in the last year.
"I look at the way this team is going about their business and even though they have yet to hit top form in my view, they are a side that has a belief running through their veins that suggests they are ready to go to the next level.
"Liverpool may have lost the Champions League final against Real Madrid in Kiev last May and all of us who love the club felt the pain of that defeat, but the run in Europe’s elite competition has changed the aura around this team for good.
"The players now believe they belong on the biggest of stages, they expect to challenge for the big trophies and most significantly, the opposition are fearful of them now.
"When you look to the Liverpool side that started last season in such uncertain fashion and compare it to the team that have been winning games in impressive fashion over the first month of this campaign, it's clear the team gave taken two or three leaps forward."
Liverpool built on the momentum established last season by spending big over the summer, with greater squad depth set to make it easier for them to challenge on multiple fronts this term.
Aldridge added ahead of a Carabao Cup and Premier League double-header with Chelsea: "Liverpool’s substitutes bench has been a real weak link over the last few years, but that is looking so strong now and it gives Klopp a real opportunity to have a right go at winning a domestic cup competition as well as pushing for the Premier League and Champions League.
"We will see two reserve teams doing battle as Chelsea come to Anfield in the Carabao Cup on Wednesday, but I’m pretty confident Klopp’s back-up players are better than Maurizio Sarri’s right now.
"Fabinho, Naby Keita, Roberto Firmino and Xherdan Shaqiri were some of the names on the Liverpool bench for the PSG game the other night, James Milner and Joe Gomez were sitting it out on Saturday [against Southampton], while Daniel Sturridge and Jordan Henderson missed out on starts against Tottenham last weekend.
"That is a lot of quality footballers to be watching from the sidelines, but it highlighted the strength Liverpool now have and it reminds me of the days when the club were the dominant force in English and European football.
"There are so many players fighting for three places in the Liverpool midfield at the moment and if anyone allows their form to dip, they will be out of the team and replaced by someone better.
"When you have this kind of quality in reserve, it makes dropping a star player a little easier for a manager and it also keeps everyone on their toes as they know their place in the side is constantly under threat."