Do monks have big ups and downs in their life?
Take a look at Ajahn Lee's autobiography, page 16 and onward.

His practice slackens, he grows disillusioned with being a monk, and he begins an obsessive debate within himself about whether to disrobe or not:


  But looking at the state of my meditation, I could see that my practice had
  grown slack. I was becoming more and more interested in worldly matters. ...
  
  One day I went up to a hollow space at the top of the chedi and sat in
  meditation. The theme of my meditation was, 'Should I stay or should I
  disrobe?' Something inside me said, 'I'd rather disrobe.'
  
  ... 'The people in the Great Metropolis aren't deva-sons or deva-daughters or
  anything. They're people and I'm a person, so why can't I make myself be like
  them?'
  
  I questioned myself back and forth like this for several days running until I
  finally decided to call a halt. If I was going to disrobe, I'd have to make
  preparations. Other people, before disrobing, got prepared by having clothes
  made and so forth, but I was going to do it differently. I was going to leave
  the monkhood in my mind first to see what it would be like.
  
  So late in the quiet of a moonlit night, I climbed up to sit inside the chedi
  and asked myself, 'If I disrobe, what will I do?' I came up with the following
  story.
  
  
    If I disrobe, I'll have to apply for a job as a clerk in the Phen Phaag Snuff and
    Stomach Medicine Company. I had a friend who had disrobed and gotten a job
    there, earning 20 baht a month, so it made sense for me to apply for a job there too.
    I'd set my mind on being honest and hard-working so that my employer would be
    satisfied with my work. I was determined that wherever I lived, I'd have to act in
    such a way that the people I lived with would think highly of me.
    
    As it turned out, the drug company finally hired me at 20 baht a month, the
    same salary as my friend. I made up my mind to budget my salary so as to have
    money left over at the end of each month, so I rented a room in the flats owned by
    Phraya Phakdi in the PratuuNam (Watergate) section of town. The rent was four
    baht a month. Water, electricity, clothing, and food would add up to another eleven
    baht, leaving me with an extra five baht at the end of each month. ...
  


I won't paste it all, as this goes on and on for several pages in insane detail as he imagined what might happen if he disrobed. I think the amount of detail is indicative of how much he wanted to disrobe right then and return to lay life.

But he concludes:


  Finally I decided to call a halt. My wife wasn't what I had hoped for, my earnings
  weren't what I had hoped for, my children weren't what I had hoped for, so I left my
  wife, was reordained and returned to the contemplative life.