Crossman at his home in Beijing.[Photo/VCG]

From then on, Crossman decided to become a volunteer.

"He asked me to give him a red armband," Liu said.

The armband is the symbol of the volunteers, and Crossman is proud of his.

"If I become a volunteer, I can make more friends," he said. "I feel special with the armband."

However, the seemingly carefree Crossman had one big problem: His visa expired and his company no longer had an office in Beijing, leaving him unable to get a new work visa.

Crossman applied for a student visa and enrolled in a Chinese language course, but that visa will expire next month.

Crossman does not want to leave Beijing.

When he first came to the city there were just two subway lines, by the end of last year it was home to 18 lines with 288 stations.

Crossman finds it hard to say if he prefers the new or the old Beijing.

"In different periods I had different lives: married life, life with children and life alone," he said. "Now I just enjoy living here."