Please explain this sentence, with “not a walk in the park” in particular: Life, sometimes you’re really not a walk in the ...

GO OUT CAMP由亚洲权威户外潮流生活媒体《GO OUT》主办。自创刊以来，《GO OUT》杂志已发行近千期，拥有遍布全球的数百万忠实读者，被誉为户外潮流 ...