In Canada, we seem to have a natural process for filtering out career politicians. If politicians survive three elections, many will leave after that third term. Ten to 12 years seems to be the unofficial limit. There are a few with 20+ years, but not many.

Being an elected representative is a very time-consuming activity. A previous local MP would fly back to Alberta every second weekend. He would attend various public events on Saturday and Sunday morning. Then fly back to Ottawa in the afternoon. It's a hard life.