The Meadow at Gardens by the Bay felt like an obstacle course last Saturday night.
As I approached the stage to catch the last few acts of this year's Laneway Festival, I had to jump to get past a heap of disposable ponchos.
They had been handed out by the organisers for use in case of rain. But most of the concert-goers had chucked them on the ground.
Earlier in the afternoon, my friend and I had found it difficult to find a clean spot to put down our mat.
The rubbish left behind by the 13,000 concert-goers was so appalling that it prompted Prime Minister Lee Hsien Loong to mention it in a Facebook post yesterday.
He wrote: "It takes continuous effort to keep Singapore clean. We need to progress from being a cleaned city to a truly clean city."
This was my third time at Laneway. I was impressed by how the music line-up, food and beverage choices, and side activities have been getting bigger and better every year.
But the litter too seems to be growing at an alarming rate each year.
You could blame the huge crowd.
You could blame the lack of bins.
You could even blame the cleaners.
But the real culprits are the litterbugs and the rest of us who allow them to get away with it.
This is Singapore's dirty shame - an ostensibly First World nation with Third World social manners.
Why is it that people from Myanmar, one of the poorest nations in South-east Asia, can pick up after themselves while Singaporeans can't or won't?
Is it because too many of us are spoiled with maids picking up after us at home and with cleaners doing so for us in public spaces?
PM Lee's use of the term "cleaned city" is telling. It was used by Dr Vivian Balakrishnan in 2012, when he told Singaporeans to have a "zero tolerance" attitude towards littering in public places.
The Minister for the Environment and Water Resources recalled at the time how, during a trip to Tokyo, Japan, he had wanted to meet the cleaners after noticing the spotless streets.
"The diplomat who accompanied me told me this was not possible - she said there were no street cleaners," he said. "She then recounted how she was scolded when she first arrived in Tokyo and tried to eat a sandwich as she strolled along the street. People stared at her, and told her pointedly not to mess up the street."
Calling Singapore a "cleaned city" means that it is the result of the work of cleaners, not its populace.
After all, a 2011 study on littering showed that more than one-third of Singaporeans would litter if it was convenient or if they would not get caught.
Mr Liak Teng Lit, chairman of the Public Hygiene Council, has strong words for such people.
"They are spoiled by efficient cleaners and expect that people will clean up after them. It's embarrassing," he told The New Paper yesterday.
"Some of them will even justify their bad behaviour by thinking that they are creating jobs for cleaners."
Mr Liak said the rest of us who do not litter need to speak out, as they do in Japan and other countries, where even children chide adults for littering.
"We should shame these people who are doing shameful things," he said.
He insisted that all it takes is a gentle reminder to the person who is littering.
And in PM Lee's own words in his Facebook post, we must remind "others to do the right thing".
So the next time you see someone litter, do not look away.
Tell the person gently but firmly that he is part of Singapore's dirty shame.