That Jermain, even after his moment of glory when he boarded the team coach home clutching not only the man of the match champagne but the match ball as well - which he kissed with delight just after the final whistle - was able to show remorse about his red card at the weekend is proof positive of his growing maturity.
"I owed it to the fans because I got sent off at the weekend; it was a bit stupid but obviously I was frustrated and I want to win," he says.
"Tonight everything went my way and I am delighted."
Jermain was determined not to be upstaged by Robert Earnshaw, who grabbed the opening two goals of the game to take his tally to 13 for the season.
Jermain's hat trick took him to seven, set on the way by the decision of Billericay referee Andy D'Urso to award David Connolly a penalty just before half time.
With that duly despatched, two second half goals, one with each foot and the second just two minutes from time - sparing the travelling fans extra-time - the hat trick was completed.
But the goals don't tell the whole story. Jermain worked hard in what was, once again, a three man forward line with Neil Mellor restored to action.
Trevor Brooking was as delighted with the hat trick as Jermain himself, and says: "Jermain had his little moment at the weekend, but we had a few words and he has reacted superbly; he attracted a lot of criticism at the time, but if he keeps putting the ball in the net like he did, he'll keep getting all the right headlines."
Nonetheless, Jermain admits that the wrong headlines were justified on Saturday, and adds: "I did give the linesman a little bit of verbal at Gillingham but you make mistakes and I have learnt from it.
"I am still young, still improving in the game, I am only 20 - and hopefully I won't get sent off again.
"But tonight I really enjoyed it, it was my first senior hat trick - hopefully the first of many - and we got the win to go through to the next round.
"It doesn't matter who scores, though. If we are playing in the cup final and someone else scores we all get medals at the end of the day.
"I am looking forward to seeing who we have got next; hopefully it is a Premiership side."
The draw for the third round of the Carling cup is on Saturday at 5.15pm, live on Sky Sports.