'Just when the teacher said the day's class had finished, I collapsed. When I woke up three hours later in hospital, I could not move my right arm and leg any more ... I could not even speak.' Recalling the day he was hit by a stroke 10 years ago, Tong Po-kwai, now 63, is calm and composed. Better known as principal Tong - he was headmaster of two secondary schools for 16 years - he said it was hard losing the ability to write. On the day he suffered the stroke, he was in a training course for principals organised by the Education Department. 'Doctors told me that my language ability was affected due to the stroke. When I saw an apple, I knew what it was, but I just could not name it.' Slowly though, the former right-hander learned to speak and write again, but with his left hand. He was able to walk again within a year. 'When I was confined to bed in hospital, I overheard the doctors telling my family that I could not walk again, so I told myself I should walk again.' He knew little about strokes before he was afflicted, although his brother had died of one aged 53. His sister also died of a stroke aged 84. 'I was just too busy, I had so much work to do for the school, and I also did a lot of voluntary work.' Doctors diagnosed the cause of his stroke as abnormal blood vessels in the brain, an inherited condition. However, Mr Tong said he did not think much about it: 'The most important thing for a stroke patient is to be open-minded and exercise our arms and legs more.' Although Mr Tong retired after the stroke, he still contributes to society by helping other stroke patients. He stepped down as chairman of the Hong Kong Stroke Association about six years ago, but still works actively within the group. 'I love singing and I found that I gained fast recovery of my speech ability through singing, so every week I would teach a group of stroke patients to sing. They love it too.'