时光皆薄凉孤情皆微凉
[shí guāng jiē bó liáng gū qíng jiē wēi liáng]
It roughly means all memories (or past times) are filled with indifference and loneliness. The person using this likely carries some sad emotions and experiences, suggesting everything fades with time including relationships and affections, leading to a cold and indifferent feeling.