Liverpool manager Gerard Houllier recently tipped the Hammers to have a good campaign coming up, but Glenn, while appreciative of his squad's efforts in his first season in charge, says that believing your own publicity can be a dangerous thing.
And the 5-4 defeat at Reading on Monday night served to reinforce the idea that desire, allied to the obvious skills the players have, is paramount.
With just one friendly left, Glenn says: "I like to think I am a fairly laid back and realistic sort of person. Last season was last season and I think that we surprised a few people, especially as the season before we got 42 points and only just stayed up.
"To get 53 points and a seventh place finish was an excellent season, but that has got to be put on the shelf - we can't live very long on the back of that.
"It is what is going to happen this year that counts and there are so many examples just recently of teams that have done well one season and suddenly, to everyone's surprise, have had a tough following one.
"I am a great admirer of what Peter Reid has done at Sunderland. After two good seasons suddenly he has one where he needs a result against Derby on the last day of the season to secure Premiership status.
"Ipswich came up as 'certainties' to be relegated and ended up qualifying for the UEFA cup and had a fantastic season - then the wheels came off.
"There are lots of examples - look at Leicester, who were almost guaranteed a top half of the table finish under Martin O' Neill.
"He had a couple of cup finals yet within a couple of years, after finishing one season badly and starting the next one badly, they are in the first division.
"History tells me you don't get too long to enjoy what has just happened. It is in the record books that we finished seventh, they can't take that away from us, but now it is a case of 'come on boys, let's get our eyes on the ball early and make sure that we have another good season'."