Have you ever seen those fugitive movies where they have the pack of bloodhounds and they rub some garment in their faces, then someone yells out "release the hounds" and the dogs all go running off in different directions sniffing at the ground and barking. Eventually, the dogs start to converge on the scent (if it's found) and trail the running fugitive. Sometimes the dogs run into water and have to be lead back to the trail on the other side. Sometimes they lose the trail altogether and have to  be leashed back up until a different fugitive is on the run or until the police get a new lead on where to search for this runaway.

I like this metaphor for agile teams because it really visualizes to me the visceral behavior of a well formed team on the "hunt" for functionality. We're given a scrap of clothing and told to get the whole person based on a brief scent of what it's all about. Hopefully for us we have users we can talk to, customers to talk to, other business people to ask about this functionality.

Additionally, sometimes we run into roadblocks. Sometimes we hit a barrier so big with a piece of functionality that we have to just pack it up (cancel the sprint) and start a new sprint. Just because this happens, it's not the end of the world. Scrum did you a favor by allowing you to say "hey, this isn't going to work because <this> is in my way".

I think many times we're so complacent with our organization that we begin saying things like "that's just the cost of doing business" or "well it's worked for 20 years, why change it?" or "that's just how such and such department does their work".

Sometimes, people see the roadblock and have a snowday while it 'works it self out'. Merely ignoring the problem and cherry picking other items off the backlog to work on. "Yea, i couldn't do that text change because legal is verifying the verbage so i went ahead and fixed that button toggle animation thing that we saw on the product backlog".

Let us as teams be those excited dogs chasing fugitives down hastily! Don't let us become giant st bernards laying on a bear rug in front of a fire lazily wasting away our day. (i have no idea where i got that, it just sounded like a complacent dog)