The first time I made my teacher angry

That is the true story in my life and when I think about it I think that I have a lot of fault and regret so much.
It happened in last two years already .it was a quite long story it was like that " I was a new student in my class and it was my first day too , so my parents took me to school and asked my teacher to helped me when I couldn't did some exercises and told them when I don't follow my teacher advice . before I went to school I thought that my teacher was woman I like woman teacher because she was kinder than man teacher ,but everything was wrong that I thought my teacher was a man and looked so angry every time so I always thought of some idea that could disturbed him and he will kicked me out from school , so I thought that I should put a tack on his chair when he came to the bathroom and I could did every thing easy and quickly, but I didn't know that my teacher stay near the class and saw me already , but he could did his feel just didn't know anything and sat on his chair . I was smiled happily and thought that my teacher was stupid because he couldn't found a student the put the tack on his chair and I thought I should had a lot of idea to disturbed him again . The new and good idea was stole his motor key and took it under the book case . he saw me did like that again, but he wasn't angry with me and did his feel look like knew nothing . One day my friend told me Sopheaktra you know when you disturbed our teacher he knew ,but he didn't blame you and always knew nothing . you shouldn't disturbed him again and shouldn't did everything against him, but I didn't follow my friend advice and I thought that I had an idea to disturbed him again my my idea was phone to him and blame to him ,but he didn't say anything .Tomorrow my teacher told me . Did you want to changed the class ? I said yes . and he asked me more question . Didn't you want to see me again ? I said yes and smiled happily and asked the one question again . Did you take me like your father ? I said no. So he went to met the director of the school and asked for stopped to taught here.at the night I thought that I had a lot of fault and I wanted to say sorry to him so I phoned to him ,but no answered and I thought that I should said sorry to him tomorrow and I did a lovely postcard to him and hoped that he wasn't angry with me .
Tomorrow I went to school and went to my class quickly when I arrived on my class all of my friends cried and I asked them why you cried ? one of friends told me our teacher died yesterday because he had an accident and died at the afternoon yesterday .
oh! I wanted to said sorry to him ,but I couldn't so I want to tell all of you should say sorry to everyone when you do something wrong . because you can't know that someone will leave from you in someday.