When students are solving problems they often turn to examples when they need assistance. Examples are helpful because they illustrate how a problem can be solved. However, when examples are very similar to the problems, students default to copying the example solutions, which hinders learning. To address this, prior work has investigated the effect of manipulating problem--example similarity, showing that learning can be increased by reducing the assistance provided by examples. We contribute to this literature by comparing two types of assistance mechanisms in the context of problem-solving activities: (1) "fade-out assistance," where initially the examples are similar to the problems but over time the problem--example similarity is reduced, and (2) "fade-in assistance" where the opposite is the case (initially the problem--example pairs have reduced similarity but the similarity is increased as more problems are solved). The fade-in assistance condition produced significantly higher learning gains than the fade-out condition and based on eye-tracking data, the fade-in group spent longer attending to the problem, particularly early on in the problem-solving session. Our conjecture that the fade-in group was engaged in more autonomous problem solving instead of copying was confirmed by exploratory analysis on a subset of the data showing that copying was initially reduced in the fade-in condition, as compared to high in the fade-out condition. Overall, our results highlight that initially struggling in a problem-solving activity results in more learning.