The Wales international had a golden opportunity to put Brendan Rodgers' side 3-1 up at Goodison Park last month, but inexplicably fired wide of the target.
Liverpool needed a late Daniel Sturridge goal to salvage a point against their neighbours after Romelu Lukaku's double had put Everton ahead.
Allen was dropped to the bench for the defeat at Hull City the following weekend, but the former Swansea made earned a recall for recent resounding victories over Norwich City and West Ham.
And the 23-year-old knows there is no point in thinking about what might of been if he had found the back of the net against Roberto Martinez's charges.
He told Liverpool's official website: "Everyone knows the disappointment and there's been a lot of talk about the miss,
"It was disappointing, but that's football and these things happen. I moved on straight away and got back to working hard, looking for the next opportunity to come.
"Obviously I had the chance to start against Norwich, which was the first start I've had at Anfield in the league for almost a year. So it was great to be back out there and be a part of a winning performance.
"I've struggled with different injury problems, but you'd hope that they're behind me now and I can focus on getting out there and playing more and more.
"The manager has just told me to be ready for when my opportunity comes and to get back to my best. That will come with game time. Nothing has changed really.
"But everything comes together with playing time, so I'm looking to getting a string of games and showing what I can do."
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