I’m sortof embarrassed even asking this, but I figured it was at least worth mentioning. Feel free to ignore it. 
When URLs break it messes with my browser history based URL completion / muscle memory so it adds a slight annoyance every time I go to a common page. The recent change of the goals URL from /username/goals to /username/ is perfectly sensible but it would be nice if the old URL redirected to the new URL.
That’s a bug! Thank you!
I’m having second thoughts about this! It’s actually easy to fix with a legacy redirect (says @bee) but, I mean, our long national nightmare of “/goals/” in the URLs is over. Let us rejoice! Your browser caches will get with the program soon enough, right? The brave new world is beeminder.com/drmaciver to see your gallery and beeminder.com/drmaciver/goals means your “goals” goal and if you don’t have such a thing then 404 is exactly the right thing to return.
Anything I’m missing? This is strictly temporary pain, right?
Basically, I’m opposed because a legacy redirect here will have to be overclever: “do you have a ‘goals’ goal? then go there, otherwise you must mean your gallery so go there.” Too much magic!
(At first @apb and @bee were inclined to disallow “goals” as a goalname to avoid any such confusion but I’m pretty excited to have solved this the right way so “goals” no longer has any special significance and you can create goals to track your goals to your heart’s delight and name them exactly what makes sense! )
Yeah, I’ll get over it eventually. I don’t really mind if you don’t add the redirect. I just wanted to register that this sort of thing has an effect, however minor.
I should mention that we do have legacy redirects for beeminder.com/username/goals/goalname to the new beeminder.com/username/goalname and similar. I think that covers all the links that might be out there in the wild.
I don’t know whether it’s indicative of a trend in recent browsers, but Safari no longer shows me the current URL unless I click in the address bar. That occasionally irritates me, given that URLs ought to be hackable, and I do edit them often enough.
Evidently I’m used to it now, because I didn’t notice this change of ours.
I suspect that this trend is brought to us by generations of programmers who thoughtlessly generated impermanent, randomish, unhackable URLs for their websites. i.e. it’s increasingly rarely useful to expose them to a user. Also: ajaxy apps doing magic unrelated to the visible URL, broken back buttons, etc. etc.
/rant
Aww. You implemented it for us anyway. Thanks. 
Oh! Wait, miscommunication between me and @bee! It was super easy but I don’t think we should do it. What if someday we want everyone to have a “goals” goal? This is setting us up for pain and confusion! Cleaner solution is to 404 just like bmndr.com/user/foo for any nonexistent slug foo. Legacy redirects are generally fine but in this case we actually want bmndr.com/user/goals to refer to a goal called “goals” and so we should just be consistent about that.
I’m probably being way too nitpicky but, well, when in doubt go with the simpler implementation, right? So no magical conditional redirect! Sorry to tease there…
Curses! Shouldn’t have pointed it out 