In the book 1984 winston got cought for acting agiants big brother. they beat him up starved him and played mind games with him but all that stuff just didnt work on winston. so they finally brought him to room 101.
when they brought him to that room they somehow figured out his biggest fear witch happends to be big nasty mean rats. they were going to let the rats eat out his face after that he finally cracked and gave up the last of his independent thought witch was the love for his girlfriend juliea so he basicly said kill her not him so he ratted her out to save him self thats how big brother crushed him.
i think that its important that he wasnt the grat hero at the end beacuse like every book has that ending and the athour wanted to show every one that not everything has a happy ending in life.
"do it to julia ! do it to julia! not me julia! i dont care what you do to her. tear her face off strip her to the bones. not me! julia! not me!" pg. 236