Some of the responses are so extreme.  I took the spirit of the thread to be, “what normal event ruins...”. Not some  catastrophic random event.   
 

‘’like a gunshot injury. Yea. That would ruin my fishing.  

It was boat issues when I had one. Now I don't have anything that ruins a trip that I can think of. I'm sure something could happen. I fell off the kayak once. I have gotten to the lake, put the kayak in before realizing I had no paddle.

Mostly people and trash left by people.

 

There was this one time about 5 years ago.. I drove 1hr 30mins to a small lake that doesn't get much pressure. Nobody was there so I pull right up at the ramp to unload my kayak from the bed of the truck. Go to open the door to get my gear and my doors locked and my keys  on the drivers seat. Couldn't get in so I had a friend get my spare key and drive it down to me. After waiting a couple hours he finally shows up and I'm anxious to get on the water so I grab my gear and realize my paddle isn't in the truck.

Not sure if that even counts as a fishing trip. I was so PO'd at myself that I packed up and went home without even wetting a line. 

52 minutes ago, They call me “Gaiter Salad” said:

Some of the responses are so extreme.  I took the spirit of the thread to be, “what normal event ruins...”. Not some  catastrophic random event.   
 

‘’like a gunshot injury. Yea. That would ruin my fishing.  

 

Well in that case.....

 

#1 Wind and waves especially when it is stronger than forecasted

 

#2 Tournaments- hate pulling up to the lake at daylight and there is a big, long line of bassboats especially when the tournament wasn't listed on the DNR website.  And the couple times this has happened- it was a HS tournament.  Gotta "grow the sport" though!

 

#3 Biting flies- they literally chased me off the water once last summer.  I was in a swarm and went on a 5 mile run thinking I'd get away from them.  Nope.  I left a couple hours sooner than I planned on since they were so annoying.  Now, I always carry a long sleeve shirt and pants in the summer in case I get into them again. 

My Degenerated Disc kills a trip more often than anything.

Trailer lights . You never know when there will be issues. 

47 minutes ago, Junk Fisherman said:

 

Well in that case.....

 

#1 Wind and waves especially when it is stronger than forecasted

 

#2 Tournaments- hate pulling up to the lake at daylight and there is a big, long line of bassboats especially when the tournament wasn't listed on the DNR website.  And the couple times this has happened- it was a HS tournament.  Gotta "grow the sport" though!

 

#3 Biting flies- they literally chased me off the water once last summer.  I was in a swarm and went on a 5 mile run thinking I'd get away from them.  Nope.  I left a couple hours sooner than I planned on since they were so annoying.  Now, I always carry a long sleeve shirt and pants in the summer in case I get into them again. 

Tournaments.  Good one!

3 hours ago, lunkerboss923 said:

Serious answer...

 

on the way to the Devil's River, in my home state of Texas, we ate at a Mexican food restaurant, they did something wrong to the beans and for the next 3 hours we drove with the windows rolled down as we all had the gas...I mean bad!!! It was miserable 3 hours! 

roll the windows up and turn on the heater, have some fun.

Snow.

I can tolerate a lot, but jet skis are not one of them... There's just no way to to truly be safe around them as unpredictable as they are. imo

Jet ski.  For their diminutive size the whip up quite the wake. Impressive. 
 

but I kayak with eyes in the back of my head. 
 

wake board boats.   Epic tsunami wakes. I always head nose first into one of those. But I think the waves knock crayfish out if the rocks

Going home! ☹️

14 hours ago, They call me “Gaiter Salad” said:

Some of the responses are so extreme.  I took the spirit of the thread to be, “what normal event ruins...”. Not some  catastrophic random event.   
 

‘’like a gunshot injury. Yea. That would ruin my fishing.  

I have been peppered by waterfowl shot while fishing 

Letting something I have no control over bother me. When thinking clear I just fish and let everything else slide past.

This past season it was convenience store/gas station workers.   Working in an environment like that with many people interacting and not wearing their masks correctly or not wearing masks at all.   I can't count how many times I've sent e-mails to corporate offices documenting negligent masking procedures in various branches of convenience stores, relatively close to my house, after coming home from a fishing trip.

People leaving trash bothers me alot. I smoke cigarettes, but I have a pouch i put my cigarette butts into. Casting and getting a irretrievable snag really sucks.

21 hours ago, fishwizzard said:

Biting insects ruin a day faster then anything for me.  I am going to breakdown and get a head net this year.  

I feel your pain. I always keep a bottle of Off! Sportsmens in my carry bag.

Whining

Busy lakes. I go to try and get away from the crowds, so I don't want to be on a busy lake if I can avoid it. 

I hate fishing around other people, unless they're friends or family. I feel like I can't concentrate on actually fishing because I have to watch my gear, my nephew's gear, worry about which way I cast, have to conversate with them if they keep asking questions, etc. I also hate trash, boaters that have the entire river that they can run up and down, yet come 20ft from the bank I'm fishing, bugs, and so on.

Being in the boat with a complainer.

Wind is about the only thing (other than injury) that will cause me to hang it up.

3 minutes ago, J Francho said:

Being in the boat with a complainer.

 

Yes....My son loves to go out fishing, but only if he is catching fish....If not he is complaining the entire time. 

 

Also being obnoxiously loud on the boat for no reason. Kids screaming really breaks my ear drums for some reason. 

When a grown man in a roto molded pointy plastic wading pool gets within casting distance. Of course when he decides it's a good idea to discuss the lipless that landed on his lap, that turns my day right around.

On 1/27/2021 at 12:21 PM, They call me “Gaiter Salad” said:

Wind.  Big wind.  
 

i do not love kayaking in wind. 

Lots of things can make fishing less fun.  But winds and lightning are about the only things that actually ruin the day for me.  I've been caught in a few pop up storms in my lifetime that had me wondering if I was going to make it home.  

 

Luckily smartphone weather apps have come along and drastically decreased the rate of those incidents.  

Rude people, always #1 on the list of trip spoilers!