I speculated the difficulty would come from finding the time to do this. I'm still on track and today's running day 2. Here's my biggest challenges so far:
1. There will never be enough time. Not giving myself an option of "I'll do it tomorrow" helps me automatically slot some time in. Even if it's 15 minutes. It's better than nothing.
2. While I have yet to try it, I'm thinking running in the morning (which means getting up earlier) will actually be easier even though it sounds awful. The later day running, which happened 2 days ago and what will happen later today, feels like my shoes are made of concrete and I'm running through thick goo. I really do function better physically (mentally is another issue) early in the morning. Getting it out of the way earlier also lifts the burden of "when am I going to do this..." This will be my next experiment, stay tuned.
The easiest thing has been the morning sun salutations. Try one day of this series when you first get up and the difference is amazing. My body wakes up, my mind wakes up, I breathe better, my posture is straighter throughout the day. This is the easy part that I crave. If you want to start simple, give that a shot.
I challenge myself... a lot.