After the result was announced, leading to the resignation of David Cameron, she was thrust into the limelight as PM and has become determined to deliver the will of the electorate saying in January 2017 "Brexit means Brexit, and we're going to make a success of it".
Asked when she realised her snap election gambit had flopped, Mrs May told BBC Radio 5 Live: "It was when I heard the exit poll".
"So I say to the other parties in the House of Commons - come forward with your own views and ideas about how we can tackle these challenges as a country", May added in her plea: "We may not agree on everything, but through debate and discussion - the hallmarks of our parliamentary democracy - ideas can be clarified and improved and a better way forward found".
May faced calls to quit from inside and outside her ruling Conservative Party after losing its majority in an election she did not need to call and which plunged Britain into the worst political instability for decades.
Yet in spite of all this, May appears to be determined to endure as premier.
May said that she had not watched the exit polls come in, claiming to have "a little bit of superstition about things like that".
She admitted that she was "devastated" by the result.
She said: "I felt, I suppose, devastated really because, as I say, I knew the campaign wasn't going perfectly but, still, the messages I was getting, people I was speaking to, but also the comments we were getting back from a lot of people that were being passed on to me were that we were going to get a better result than we did".
A year since she set out her vision on the steps of 10 Downing Street after becoming Prime Minister, May now leads a minority government, shored up by a deal with the Democratic Unionist Party of Northern Ireland.
May during the campaign emphasised her "strong and stable leadership" as Britain headed into Brexit, but she was accused of a robotic performance, relying too much on soundbites.
"When the result came through it was complete shock", May added.
She said: "He was there through the night with his constituents - I saw a Jeremy Corbyn there was was a good constituency MP". "I'd called it because of concerns about how we were going to go forwards, particularly on Brexit".