It is apparent that in the show where he understandably gets sad, as he is a sensitive soul as well.
However, with him being a character that the audience will forever root for, it is difficult to see him upset. In fact, it is fair to argue that SpongeBob goes through a lot of hard moments in the series. These specific circumstances are ones that fans often most, as they tend to put SpongeBob in very hard situations.
Nobody even wants to see the most popular sponge in the world cry and struggle, so it is quite easy to feel empathy for him.
When Gary Runs Away From Him
When SpongeBob becomes too focused on his brand new Mermaid Man and Barnacle Boy paddleball set, he neglects Gary. After not feeding him for days, Gary ends up running away and leaves a sad note.
Although SpongeBob certainly warrants blame for Gary leaving, it is hard not to feel some sort of sympathy for him when he cries for the entire episode. The flashback moments between the pair also add to the melancholy of the episode. Thankfully SpongeBob accepts responsibility and eventually finds him.
When Nematodes Drink His House
When a group of nematodes causes havoc around Bikini Bottom, SpongeBob is perhaps the biggest victim of all. This is due to the fact that they drink the juice from his pineapple home, which makes it disappear entirely.
As a result of this, SpongeBob now finds himself without a home, meaning he has to briefly stay at Patrick's. However, after realizing this living arrangement would not work out, he decides to move back to his parents' house, which he is very upset about. Thankfully, though, his tears help to bring his house back.
When Flats Bullies Him
When Flats s Mrs. Puff's Boating School class, SpongeBob immediately introduces himself in a very kind manner and tries to be his friend. However, it turns out to be the wrong decision on his end, as Flats then tells him that he is going to kick his butt.
After this occurs, SpongeBob spends the entire episode in immense fear, as Flats is a rather intimidating figure. Mrs. Puff even escalates the situation by using SpongeBob's name when he addresses the situation. However, once Flats tries to beat him up, SpongeBob thankfully does not feel a thing because of his sponge body. Still, it was, nevertheless, horrible to watch SpongeBob's immense fear grow.
When Bubble Bass Lies About The Pickles
Bubble Bass is a very difficult customer, which sees SpongeBob become competitive with him when he makes his Krabby Patty. However, Bubble Bass gloats when SpongeBob forgets to put pickles on it. This causes SpongeBob great stress, and he even forgets how to make the burger altogether.
SpongeBob loses complete confidence in himself and even stops going to work. When he does how to do the recipe again, Bubble Bass tries to say he forgot the pickles again. Yet, SpongeBob discovers that he has been hiding them under his tongue. While everyone was relieved to see SpongeBob's confidence come back, it was still hard not to feel bad for SpongeBob before this.
When Mr. Krabs Bets His Contract In Poker
SpongeBob loves working for the Krusty Krab more than anything in the world. Thus, his heart is absolutely broken when Mr. Krabs bets his contract in a poker game with Plankton and loses. Thus, SpongeBob now needs to work at the Chum Bucket and hates every second of it.
It is especially sad when he sings "This Grill Is Not A Home" with Mr. Krabs and cries immediately after. It is just another example of SpongeBob feeling the negative impact of Mr. Krabs' greed.
When Squidward Plays A Cruel April Fools Joke On Him
SpongeBob loves April Fools Day and plays a bunch of small pranks on people at the Krusty Krab. Although SpongeBob is having fun and laughing, Squidward becomes quite annoyed with him and decides to play one on him out of spite.
However, Squidward takes it way too far, as he ties SpongeBob up with a rope. This ends up pulling him and putting him in extreme danger, as he hits into the walls and ceiling multiple times. Squidward then catches him with the trash barrel and calls him a little sausage, which leads to SpongeBob running away and crying.
When He Thinks He Is Ugly
When SpongeBob is out of ice cream, he decides to make a sundae out of ketchup, onions, and a house plant. This results in him having atrocious breath, which ends up scaring the citizens of Bikini Bottom.
However, SpongeBob is under the impression that he is ugly and becomes extremely sad. He spends the entire episode crying over this false belief, and it doesn't help that Patrick is the one who eggs this theory on. Thankfully, he does realize it actually is his breath after Patrick eats the sundae too, but it was horrible to see his self-esteem at an all-time low.
When Sandy Gets Him Fired
When SpongeBob and Sandy's newfound karate hobby in karate becomes a distraction for SpongeBob while working, Mr. Krabs tells him he needs to stop or he will be fired. However, the pair have a hard time stopping their favorite hobby.
While having a picnic, Sandy no longer can hold back and karate chops SpongeBob. This leads to the pair fighting again, but Mr. Krabs sadly catches them doing so. Thus, this leads to SpongeBob getting fired. It is hard for the audience not to feel bad for him, as he cries and runs around while doing so.
When Patrick Becomes Too Smart To Be His Friend
After falling off a cliff chasing a jellyfish, Patrick loses the top of his head. When SpongeBob puts it back on him, Patrick suddenly becomes a genius. This ends up being a bad thing, though, as it leads to Patrick growing apart from SpongeBob.
The two best buddies just don't relate to one another anymore, which leads to Patrick thinking it is best for them to no longer be friends. This, ultimately, breaks SpongeBob's heart. However, once they find out the top of his head is actually brain coral, Patrick immediately decides to switch it with his old one. Thus, the two become friends yet again.
When Squidward Gets Him Fired
When Mr. Krabs starts billing Squidward and SpongeBob for unreasonable things, like breathing and standing, this leads Squidward to convince SpongeBob to go on strike with him.
SpongeBob does not know what a strike means, but he gladly s Squidward to spend more time with him. However, this leads to SpongeBob getting fired when he tells Mr. Krabs about it. He then cries, which leads to the viewers feeling a wave of sympathy for him because he loves working for the Krusty Krab.