Why do number patterns confuse me?

Number sequences are hard because the rule can operate in many ways: constant differences, changing differences, multiplication, alternating series, position-based formulas or combinations. Without a systematic checking order, you rely on recognizing the rule instantly, which works for familiar patterns and fails otherwise. Working through differences in a fixed order solves most items.

Each check requires holding the original numbers plus the computed values, which quickly fills working memory. Writing the differences under the sequence removes that constraint and makes patterns visible. People who find these items easy usually recognize common families quickly, having seen them many times, which is familiarity rather than a different kind of mind.

Any finite sequence can be continued by more than one rule, which is a known criticism of sequence items. Well-designed tests choose sequences where one rule is clearly simpler than alternatives, but ambiguity is a real limitation. If you find a rule that fits every given term, your answer is defensible even if the test expected another.