Suffering on the Streets?

With four weeks to go until my first Marathon (Canberra) I am wondering just how much suffering will be involved on the actual day...so far we have done a max 30km long run and while the last five kms hurt i wouldnt say we really suffered...we do 34 this weekend and i feel pretty good about it..the last five k's of the longs runs has hurt but the only bad experience was when we tried to run 30kms in 32C and konked out at 24kms due to dehydration

Will there be mental anguish? If so, Ive read that it's better to focus on external dissociation than internal...looking around you, running to the next tree, talking to your partners, rather than focus on a mantra or switch on the music.....I plan to test this on the 43 coming up this weekend..