解释:初次经历,通常是不容易的

a first experience of something, usually something difficult or unpleasant.

My son's just had his first visit to the dentist. He stood up to this baptism of fire very well.

Mary's had her baptism of fire as a teacher. She was assigned to the worst class in the school.
来源:可可英语 http://www.kekenet.com/kouyu/201001/93800.shtml