You know because a loss like last night's induces something in between annoyance and seething.
Earlier in April each game still feels a bit like a pleasant surprise, a way to resume the proper rhythms of life after a long winter. Earlier in April, if Shawn Green failed to advance Moises Alou from second as the tying run with none out down 1 in the 8th (for instance), your reaction might well be muted by some part of your brain that's thinking, “Hey! It's Shawn Green! In a Mets uniform! The Mets are on!” Earlier in April, if Jose Valentin then followed such a failure with his own harmless fly ball (as a hypothetical), you might drift off into a reverie about Mets who changed uniform numbers.
But not now. With April running out, failures like those seem borderline criminal, part of a flat, lifeless loss to a team the Mets should overpower. The honeymoon period's over and the main business of 2007 is at hand, and no other considerations — not even thinking that Oliver Perez pitching pretty well except for one bad pitch or that Joe Smith is headed for bigger things — can change that storyline.