When I don't live up to those expectations, I feel a twinge of guilt and I resolve to do better. Then I'm thankful to have someone who is paying attention.
In my experience in Evangelical churches, people seem a little fuzzy on where other people's boundaries are. Even as first-time visitors, Sarah and I are nearly always treated to this wonderful gem after shaking hands and exchanging names:
Congregant: So, do you guys have any kids yet?
One of us: Nope, we have a dog and a cat.
Congregant: Oh, well hopefully soon!
Another variation involves asking when we plan on having kids, and asserting that God will change our minds.
If we attend for any period of time, eventually someone discovers that I play guitar.
Person: You play guitar? Awesome! We'll have to get you on the worship team sometime!
Note the phrasing: "yet" indicates an expectation that we will have kids; invoking God makes it a moral mandate. "We'll have to get you..." assumes that possessing a skill means I want to lend it to them and destroys any concept of self-determination I may have.
And it continues. What night is good for you to join a small group? What are you bringing for the potluck? When are you taking a turn in the nursery (this one typically only applies to Sarah)?
It applies at every stage of life. I remember adults constantly asking other people's kids about their romantic lives, usually to express their distaste for teenage dating... and then, the minute these kids graduated from high school, asking when they were going to meet someone of the opposite gender and embark on a heterosexual marriage.
They'd ask what college we wanted to go to, just make sure we were planning on a Christian college. Bonus points if it was Bible college.
They'd ask what music we were listening to and whether it was "Christian".
They'd ask why we would possibly want to watch R-rated movies.
They'd ask anything, and they would do it in such a way that it expressed their opinion of what we should be doing.
Eventually, they'd drop the pretense and start prescribing. And then one morning you wake up and you realize one of two things:
1) The life you lead has been tailored to the preferences of a bunch of people you barely know.
2) You have been lying about who you are to an awful lot of people.
Either way, the only thing that eases the tension is to cut and run.