Why is time out so short?

Haven't been posting very long, but find the time out when composing a reply very irritating. Can't be just me who has to answer door, feed dogs, have a cup of tea, only to find that cannot submit. I know  it says use word and paste, but seems a bit strange to me doing it that way.

Online banking time outs I can understand, but I am a little puzzled why it happens on here. I will also add that I am no computer expert, so it could be something that I am doing that is at fault. Help please?