What do you do for fun outside the house?
this sounds like a present tense question, which makes answering the big question hard as there isn't nearly as many things to do here as there were in other places i've lived.
so, lately, since i noticed a couple years ago that the amount of time i spent outside getting some direct sunlight into my skin had a tremendous effect on my moods (meaning it elevated them), i've just been taking books, my laptop, etc. outside and lying on a lounge chair for a few hours.
winter can make me feel like shit. i get bored easily, and like you said, in a rut, when it's cold outside. i prefer sunlight and lots of it. thank god for the internet, tv, and books, or i'd go insane.
when there was more to do where i lived, i enjoyed:
going to antique stores or any little stores that could contain hidden treasures. even the salvation army thrift stores.
finding new libraries and exploring them
walking or driving someplace i'd never been before just to see what's there and maybe talk with the people in the convenience stores
going to games or to the park and 'people-watching'
finding out of the way rivers and large creeks with rocks all over the shore and looking for indian treasures, special rocks/crystals, fossils, etc.
randomly taking trips anywhere, anywhere. just jump in the car and go. i've been to NYC twice and tons of other places doing this. all i need is the vehicle, gas money, and a friend to crash with, and i'm gone.
finding little book stores. i've found a lot of first editions and old comics that i treasure to this day.
i'm sure there's more, but i have to wrap this up for now.
activities have brought you most joy and excitement in life?
see above. those are some 'concrete examples' that you asked for.
you ever been able to sustain that sense of fun for a relatively long period? How?
if you mean, have i been able to have fun period for a relatively long period of time, then yes. i have, but it's not a usual thing. i just tend to explore my surroundings either outside or inside until i find myself doing three or more things at once. it's not something i try to do.
also, i have the habit of seeing everything as something that can be tweaked. if something interests me on tv, the thought of buying it if i can make it irks me, so i make it myself but better.
it's hard not to look around and see how something can be better.
ENTP sense of a boredom is well documented and I relate a lot to ENTP in certain ways, this being one of them.
i'm somewhat sad when i'm bored. i can't even imagine just sitting in a blank room with nothing to see/hear/play with. i'd go nuts. oh, i could lie there for a bit and imagine, but then i'd start trying to invent a way to get the fuck out and as soon as possible.
in the house, i start going through all of the books i haven't gotten to yet and begin learning/doing something new (internet is great for this).
for instance, building an indoor waterfall, creating medicine with herbs/oil/alcohol/etc, how to fix/tweak drywall, how to fix electronics, etc. etc. etc.
