Knowing how students approach learning in higher education contexts is key to promote learning strategies that are effective in the long run. Previous research has concluded that students often use ineffective learning strategies but believe them to be effective--a phenomenon known as metacognitive illusion. In a bid to broaden the perspective on students' use of learning strategies, this study draws on the notion of self-regulated learning as a theoretical lens. A questionnaire, comprising both open-ended and closed-ended questions, was developed to gather data from 416 engineering students. The questionnaire was geared towards (1) mapping what learning strategies students use in a real-world setting, in real courses, (2) probing their metacognitive awareness of the effectiveness of various learning strategies and (3) investigating why students choose certain learning strategies. We also compared which learning strategies the engineering students chose across programs and types of courses. The findings reveal a complex picture of why students sometimes use seemingly ineffective learning strategies, and we conclude that this is not always due to metacognitive illusion. It is instead often linked to attempts to regulate behaviour, motivation and/or learning context, sometimes in response to the context. This study adds to the current HE research investigating students' abilities to reflect on, assess and take control of their learning in an effective way, confirming that students need explicit guidance.