I think this is a really interesting concept and I will outline this with three examples below:
1. You're a single parent and have 2 young kids and you get sick. Do you get to choose not to prepare them a meal, not to bathe them, not to read to them, not to play with them, not to put them to bed... Not really! You may modify what you do and how you do it but you've still got to fulfill your responsibilities. Even though your circumstances have changed (you got sick) you still have expectations (taking care of your kids) that you have to fulfill. So built into this idea of expectations is the idea that responsibilities exist (or if they don't maybe they should!). What's the cost of making modifications to your regular routine? Said another way, what are the implications for yourself, your kids, your relationships with them, and your routine based on making these modifications. Minimal. You may not do everything you normally do but you'll still get accomplish the essentials.
2. What if you're a salaried employee and you're sick and you take the day off. What are the implications to you, your employer, your job? You get the day off, sick days are part of your job so your employer expects that some sick days will probably be taken. Finally your job is still there for you when you're back to full health. In this case, even though circumstances have changed (you've gotten sick) there are expectations that accommodate this change in circumstance. Again, the impact in your life, your employers life, and your job is minimal.
3. Let's imagine you're a business owner and you have employees that work for you. Let's imagine again that you've become sick but on the day that you're sick you're supposed to have a big meeting with a very important prospective client. Now here's the thing, just like in the other examples, your circumstances have changed, however, have your expectations changed? Or, said another way, can you afford to change your expectations (or responsibilities)? Meaning can you afford to accommodate your sickness based on the fact that a big portion of your job and your job's business depends on you to be there that given day. The overall impact to your life, your business, and your employees is huge if you're not able to be there that day.
Let's reflect a little on these examples and dive a little deeper. In examples 1 and 3 (the parent and business owner) are very independent, meaning that if they aren't there to do their jobs there are potentially huge implications for their lives, the lives of the people around them directly involved in the situation (kids and employees). Now, in example 1 the implications were small based on the parent just getting sick but they would have been a lot bigger if they parent had become more seriously ill, especially if the parent didn't have a support network of family and friends to lean on to support the change in her circumstances.
In example 2, the salaried employee has less independence. This doesn't mean they don't have autonomy in their job it simply means that their role can be filled by another individual. If you want to look at it this way, the salaried employee's presence is more dispensable than that of the parent and business owner. For the parent and business owner, when circumstances change (ie. getting sick) the leniency in modifying or changing their expectations or responsibility is very small. For the salaried employee, the leniency in modifying or changing expectations based on circumstance is much larger.
Expectations can change based on circumstance but one must take into consideration the cost (implications) of this change on the person, business, and others lives that will be directly impacted by this change.