Student :" what's the marriage?"

 Teacher :" Go to the jungle and bring me the tallest tree.But remember u can't come back"

He went and after a short time, he came back with a tree.

Teacher: "what's happen?" Student:"Iwent to the jungle and choose the first tall tree ,for I was afraid if I go forward , may be I can't find a tall tree."

Teacher :"Marriage is this"