Expectations - when do you set them?

Expectations are different than goals. Expectations, in my head, align with the outcomes of any or all actions. Setting expectations may be good in some scenarios, and not setting them could be inevitable in other scenarios. How do you navigate through these scenarios so as to not get too disappointed, and yet have enough pleasant surprises?

When I started running, the expectation I set (with myself) up front was that I would go out and run - three times a week for however long it takes for me to get to the half marathon mark. What I didn't consider was that sticking it through will be difficult - I cant sneak in a run when I am in class from 8 am - 10 pm, I cannot run (painlessly) after a night out with classmates (which happens way too often with one drink too many), I don't want to run when it is cold and dreadful outside (which in Pittsburgh, it is for a majority of the year going forward). Even though I knew it would be a long journey, I expected to be farther along in the process than I am right now, so now I am (a wee bit disappointed in myself) changing what I had set earlier to just getting out and running three times a week (no caveat about getting good - I will run thrice a week, or try to, forever technically).

A couple things that have been keeping me from running painlessly, have been cramps and side stitches. Now I know that I should be stretching before I run, and breathe well while I run, but that was a bit of hear-say. When I looked into it further, I found this video very useful, where the doc talks about the types of cramping, how they are caused, and what to do to prevent them, and side stitches. Now, I expect to take the steps that will ensure that I don't face the same problems going forward (well otherwise I'm just plain lazy and like to be in pain).

Business school teaches us to set expectations up front - before a meeting, before starting a group project, and before signing up for a class. This helps get everyone on the same page in terms of objectives, and results. I wonder how or if this can work outside the work/ classroom setting - can you ever set expectations for a friendship/ relationship? It seems so artificial (imagine telling your new friend that  you expect him/her to check in once a week at certain date/time! yuck!) and yet we all have certain expectations that we have in our head about knowing whats going on in your friend's life, about hearing from your significant other regularly, about what we do or don't do for family/ friends ("No, I won't do your dishes."). So the best relationships come out of aligned expectations, but would the bad ones be any better if this whole process of "setting expectations" explicitly happened? I wonder.

Bottom line: Expectations change. Be flexible.