The research found of those, 73 per cent have ‘made do’ with their partner because their ‘true love’ slipped through their fingers.
And a quarter of all adults have been in love with two people at the same time.
But the detailed study revealed 17 per cent of the 2,000 adults polled said they have met the love of their life since they got together with their long-term partner.
And some 46 per cent said they would be prepared to leave their spouse or partner to be with their true love.
Men are more loyal to their partners than women with 37 per cent saying they would stay in the relationship for their partner’s sake.
The poll by Siemens Festival Nights, a unique three day event showcasing three different operas, found the average person has fallen head over heels in love just twice in their life and has been left heartbroken once.
But an unfortunate one in 20 adults has been heartbroken more than five times in their life.
For 60 per cent of those questioned it took just 10 weeks to know that someone is Mr or Mrs Right, the poll found.
Claire Jarvis, Director of Communications for Siemens said: “The survey highlighted some colourful revelations about people’s love lives.
“The results showed it can be hard to find ‘the one’ and although the general perception is that women tend to fall in love more often than men, it was intriguing to see that in reality both men and women fall in love on average two times in their life.
“What is alarming is that so many people claim to be in long term relationships or even married to someone who isn’t the true love of their life.
“And if there are people out there who are genuinely in love with two people at the same time, they must face a huge dilemma.
“Interestingly, more than half of those polled thought they have been in love on occasions but looking back don’t believe it was the ‘real thing’.”
The survey also found that the typical adult fell in love for the first time at the tender age of 19 and dated four to five people before they met ‘the one’.
The study also showed that for nearly 75 per cent of the adults polled the definition of love changes as they got older.
Claire Jarvis added: “Although many of the adults polled said they weren’t with their true love, the majority claimed to be head over heels with their current partner which is really encouraging”
“Love is a fundamental in everyone’s life and a dominant theme in all forms of art and culture.
“Many famous opera stories like La Traviata, and the Magic Flute centre on a powerful love story and our upcoming events at the Crystal in London which are open to the public are no exception.
“We hope adults and children alike will take advantage of this festival and enjoy opera at its finest, in a relaxed and welcoming outdoor setting.”