Once a little girl was sitting in kitchen watching her mother preparing fish for lunch. She saw that her mother took the fish and cut it's head and tail before placing it into a baking pan. Little girl was curious to see this. She questioned her mother, "Ma, why did you cut the head and tail of fish before?"Little girl's mother thought for a while and then said, "I don't know the reason but it has always been done like this.. your grandma did it same way.."Little girl was still curious as this answer was not satisfactory for her. She thought for a while and then went to her grandma. Little girl went to her and said, "Grandma.. why is fish head and tail cut off before baking it??"Grandma was surprised at question. She thought for a while and said, "I don't know the reason.. my mother taught me to cook fish that way only.."Little girl still wanted to know about it. So she went to her great grandma who was outside sitting in the porch. Little girl went to her and asked same question, "Grandma, why did you cut off head and tail of fish before baking??"Great grandma thought for a while and replied, "Oh.. that it's because my baking pan was too small to fit in the whole fish.." 
Traditions pass from one generation to another but some routine that we follow might be started in past just because of environment they lived in. 