I'm not sure at what point it was that I thought it would be great to run 10 miles to work before my first coffee or pick my outfits based on what I could cram into my running rucksack.
But, at some point over the last four months, I did something the Jackie of two years ago would never have thought possible.
I fell in love...
...with a little thing called running (oh, and compression tights and moulded insoles and basically any form of tight-fitting clothing).
Having officially made it to the first proper taper of my entire life, I'm already starting to miss the thought of long Sunday runs in the rain and spending hours wondering whether I should eat another gel or locate the nearest toilet (what is this rare thing called a lie-in?).
To fill the time spent not exercising, I have started to reflect on what exactly this love affair with sweat has done to my life.
And I think I may at last understand the meaning of the phrase 'love is blind'.
Can you spot the signs?
1)You think this is the right amount of pasta for one person - as a starter
2)You think glaring at - or preferably running away from - people with colds is acceptable behaviour
3)You think this is a 'good post' day
4)You think the mark of a great hotel is whether or not it has recommended running routes on its website (I guess the fact you think it normal to actually pack running kit also deserves a mention)
5)You think a good Saturday night is sleeping in a cheap hotel in your running kit (no room for pyjamas) so you can get up early to run 20 miles in a place you don't know - just for one of these...
6)You think a half marathon is short
7)You think you're winning when your goodie bag contains one of these...
8)You think you should choose your hairstyle based on whether it will stay put on a run (in fairness, chemo had a part to play in my pixie)
9)Your think everyone on Twitter needs to see your running number
10)You think heels are an instrument of torture
11)You think one day you might master the running selfie (or maybe not)
12) You think talking about the efficiency of the bag drop is good chat
13) You think it's fun to rank your medals (can you beat this beauty?)
14) You think a holiday is a week without a race in the diary
15)You think this is a snack
16)You think there are too many pictures of you grimacing when running in the public domain (so much so I won't be adding any here)
17)You think everyone wants the link to your fundraising page (here it is again in case you didn't spot it on Facebook, Twitter or your email)
18)You think running 26.2 miles round the streets of London will be the best day of your entire life
If I make it to the starting line, I'll let you know whether number 18 turns this love affair into a lifelong passion...
...or a very very bad dream.