But he is delighted that club team mate Michael Carrick scored the winner - a tap-in from six yards out - against Holland in their European Championship play off second-leg on Tuesday, and jokes: "I said: 'Mike, what were you doing there?' and he said: 'just doing your job with a little poach'.
"I don't even know what he was doing and I don't know what the celebration was about but I am glad a West Ham team mate got the goal.
"He is getting a few goals now so maybe I will have to take his job and start spraying some 40 yard passes around!
"To be honest, I really enjoyed it; it was a quick game and it was a bit difficult to get the ball off them, but it was a lot better in the second half and the atmosphere was great.
"We had got the two goals away from home so they had to come at us."
Jermain is not in the least jealous about Michael getting a regular berth in the first team while he comes on from the bench, and says: "Not at all - I think it is good that young players are playing, and if they weren't I wouldn't think I was at the right club where youngsters get a chance."
Jermain fervently hopes that fellow under-21 team mate Joe Cole returns soon, and says: "He has been out a long time and it takes a little bit of time to get sharpness and match fitness back but hopefully he can do so with the World Cup coming up.
"We want to see Joe back for West Ham and the under-21s first but he is good enough for the senior squad.
"Everyone is saying there is a problem on the left hand side and he could fill it, though I thought Trevor did really well the other day for England.
"He has been playing really well even though people are talking about him leaving."
He hopes that Trevor changes his mind on that score, and says: "If we are winning games and doing well I can't see why you would want to leave; when the team is not doing so well you might think differently.
"He is one of our best players and I would love him to stay at the club; he just likes playing football."
Meanwhile, Jermain is looking forward to his first return to the Valley as a senior player with West Ham and he says: "I spoke to my mum about it yesterday; I haven't been there for ages and it will be quite interesting to see what happens."
He joined West Ham after a compensation fee was set by a tribunal two seasons ago; that fee could rise to £1.65m if he goes on to play for England.
He admits he expects a stormy reception from Addicks fans disappointed by his decision to go, and says: "To be honest, when I first signed for West Ham I played in a reserve game and the stick was mad.
"It was unbelievable, but it probably won't bother me at all if I get it again, which I probably will.
"When the manager says 'get warmed up' and you are running towards the crowd, even though you are thinking about the game it is different when you are playing.
"If I do get on the pitch it will make me want to score more and the sooner I get on the pitch the better!
"But just because I left the club doesn't mean I don't respect them; of course I do and I enjoyed my time there.
"I just wanted a change, and it was the season when West Ham won the Youth Cup; I wanted to be a part of those great young players really and I spoke to people like Amos Foyewa, who I knew from school.
"There were good players at Charlton but I'd been there a long time coming through the ranks.
"But I still speak to a lot of the lads there such as Scott Parker; I have nothing against the lads or the team, and they are a decent side as they showed against Arsenal when they won 4-2.
The fee for Jermain's transfer, a huge chunk of which West Ham have already paid, was considered by many as excessive for a 16 year and Jermain recalls: "It was mad, really. I was 16 when I joined and I suppose it was pressure but I tried not to think about the price tag and just get on with playing football because that's what it's about.
"I was just glad when it was over; everyone was talking about it, but you don't want to be reading about yourself in the papers, you just want to play football.
"I'm happy at West Ham and that is all that matters; as long as you are happy then that is good."
But does he think he would have made more Premiership starts if he had stayed at Charlton?
"A lot of people say that," he says, "and you never know; if you are good enough and playing well you can play for any club, I suppose.
"I'm having to be patient and see what happens; Glenn talks to me all the time and I'm still young."