Two main reasons why Helga kept her love for Arnold a secret:
Reason #1: Fear of rejection by Arnold
– In the episode “Monkey business”, Helga has a dream that Arnold rejects monkey-Helga after she confesses her love to him. This scene was part of Helga’s nightmare, meaning rejection is a bad thing for Helga.
– The advice you give is often reflects the beliefs that you hold, and that’s no exception with Helga. Helga dishes out her advice to some of the gang’s problems in “Deconstructing Arnold”, and that allows us to give us some insight into her personality. Helga’s advice to Rhonda on how to get rid of her admirer, Curly, was to have Rhonda confess to him, which should “repulse” him and therefore get Curly off her back. This advice is a parallel to Helga’s view of her relationship with Arnold. She thinks that by confessing her love for Arnold (and putting him “on the spot”), Arnold, too, will be repulsed and as a result, Helga will lose Arnold forever.
Helga has to be perfect in order for Arnold to love him; believes Arnold will not love her for who she is
– In “Monkey business”, Arnold’s rejection line to Helga was: “But you’re not Helga. You’re a monkey! A monkey-girl!” Helga believes that Arnold will not love her whole-heartedly, or completely. She believes she has to be perfect in order for him to love him. In other words, humans are more perfect than monkeys.
– Remember how Helga is always competing with Lila for Arnold’s love? It got so bad to the point where Helga tried to act/look like Lila in “Helga’s masquerade”. Helga thought that by being like Lila, who is practically the personification of perfection, she can win Arnold’s affection. (Helga’s line of thought during “Helga’s masquerade” was: be more like Lila = be more perfect = win Arnold’s love). Luckily, Helga had learned her lesson by the end of this episode: that Arnold should love the one who’s perfect for him (i.e. Helga), not one who seems perfect (i.e. Lila). Helga demonstrates that she has learned this lesson in the episode “Married”, with her soliloquy behind the dumpster.
Therefore, with the last point being said, the Helga after her masquerade is different from the Helga before said masquerade. She will now try to win Arnold’s affection by getting her to love her for who she is, as opposed to getting him to love a superficially-perfect Helga.
Reason #2: Fear of humiliation by others
– Helga’s soliloquys are always a goldmine to help you understand the characters and themes of “Hey Arnold”. Taken from her soliloquy in “Monkey business”, she hopes that she will not have to confess her love for Arnold in the near future, as that would be “embarrasing and humiliating”.
– Where did this fear of humiliation come from? Let’s jump back to Helga’s preschool years in the episode “Helga on the couch”, where she first develops her love for Arnold. The moment Helga showed public signs of liking Arnold (i.e. swooning after Arnold gave her his cookies), her preschool peers laughed at her. She immediately decided to stop this barrage of laughter via violence, thus beginning her reign as the school bully.
Given her reputation as a tough school bully, it is now even harder for Helga to overcome her fear of humiliation and fully accept her contrasting, tender feelings for Arnold. After “Hey Arnold! The Movie”, this fear of humilation will now be her greatest obstacle to overcome in order to face her feelings for Arnold.