In The Legend of Zelda: Oracle of Seasons, there's a shovel you can get that basically digs up grass tiles, occasionally giving you rupees or hearts or something, and really isn't that useful except for a couple puzzles.
That won't stop me from going outside and digging up every single patch of earth I could find, scouring the landscape of grass and other not-ugly things and replacing it with holes in the ground. If the world didn't reset every time I went to another area, the world would be dark and desolate, grass would be scarce and children everywhere falling into the holes I've dug. People's crops would be overturned, cattle starving without the grass they need, and as such entire species would become extinct, and the world would fall into disrepair. Those RPG villains will never have done as much damage as I have done.
I'd get a lot of money, though.
I assume many people who played Aria of Sorrow had a similar experience.
Attention: possible spoilers and enraged conversationing.
First, some backstory:
[19:55:41] Miriam: I killed 50 chronomages and all i got was this t-shirt
[19:55:42] Miriam: and pudding
[19:56:12] Miriam: and the 51st dropped a soul yay
[19:56:29] Miriam: COMPLAINING ACTUALLY WORKS
Now the actual thing: (after half an hour of trying to find a specific enemy and trying to get its soul)
[21:33:51] Miriam: how do you catch sky fish?
[21:44:18] Miriam: I mean, you need that soul to go through the waterfall, right? //Note: Still trying to get it here
[21:45:26] Miriam: ... oh you don't //Not anymore!
[21:45:28] Miriam: ... FUCK
[21:45:45] Griffin .-.: Are you okay
[21:45:55] Miriam: i i thought
[21:45:57] Miriam: they
[21:46:13] Miriam: they made such a huge deal of timestopping and fast enemies
[21:46:14] Miriam: and
[21:46:15] Miriam: i thought
[21:46:38] Miriam: ... sky fish gave you sonic-tier running skills so you can go through the waterfall
[21:46:52] Miriam: ... but all it does is give you stats
[21:46:52] Miriam: why
[21:47:01] Miriam: ... like
[21:47:11] Miriam: MESSAGE FROM ARIKADO: YOU CAN STOP TIME
[21:47:26] Griffin .-.: It was all a lie
[21:47:32] Miriam: MESSAGE FROM ARIKADO: THERES AN ENEMY THAT CAN ONLY BE KILLED BY TIMESTOPPING
[21:47:56] Miriam: MESSAGE FROM ARIKADO: BLAH BLAH BLAH WATER SURFACE BLAH BLAH THROUGH WATERFALL
[21:48:00] Miriam: ...
[21:48:18] Griffin .-.: Calm down ; ;
[21:49:43] Miriam: i am perfectly calm
[21:49:47] Miriam: perfectly calm
[21:49:51] Miriam: perfectly calm
[21:49:52] Miriam: like
[21:49:58] Miriam: totally perfectly calm
[21:50:06] Griffin .-.: Okay okay if you say so <<
[21:55:38] Miriam: so i assume the pictures of shiva dude, something like a knight or so and the lesser demon from SotN are a hint, then
[21:55:56] Miriam: ...
[21:56:05] Miriam: THAT STUPID SKY FISH WAS A RED HERRING ARRRRGH
[21:56:12] Miriam: and i made a horrible joke
[21:56:47] Miriam: like
[21:56:49] Miriam: herring
[21:56:56] Miriam: fish
I assume many people who played Aria of Sorrow had a similar experience.
Attention: possible spoilers and enraged conversationing.
-snip-
It's not entirely pointless.
Don't you need to get the Sky Fish soul anyway to finish getting 100% souls and get the Chaos Ring?
(http://i.imgur.com/kW47uPr.png)
I delayed an entire battle just to get a shot of this statue of a confused skeleton.
Worth it.
The inclusion of the dreaded Cucco to my MUGEN rooster roaster roster.(Is MUGEN even considered a game?)
Because I saw vids of those things. Not only is it funny to put a chicken in the battlefield...
... but it's also down-right hilariously humilating to have an invulnerable flock of fowl defeat pretty much anyone(even Omega Zero!). THAT'S why they're so dreaded in MUGEN.
Recently?
Rayman 2: The Great Escape on Nintendo 64 - collecting all 1000 lums.
[Yes 1000, thanks Blathers.]
It was painful but somehow worth in a really weird way.
I had the PS1 version, that only had 800 lums but once you collected enough of them it did unlock a bonus stage.
learning how to do the combo's in looney tunes acme arsenal... Wii version...
Killing the giant samurai in mini ninjas with caltrops. took longer than the entire rest of the game combined.
crafting a shield bearer in hearthstone
Carrying around the target dummies in fistful of frags
dancing, shooting to the music.
Collecting statless weapons in Kid icarus Uprising
Deliberately skipping Macguffins in countless 3d platformers so that I could see the NPC say "you need more macguffins"
deliberately not finishing a level so that I could see the intro scene again.
WOOO take it from me Spyro, Never, spend a week, in a cage. Next thing you know your whole island will be knee deep in rynocs, well, gotta go Mr. Laserblaster and I gotta WHOOOLE lotta work to do.
(from memory)