Effective data visualization is essential for digital self-tracking to help users gain insights into their behavior and habits. Personalized visualizations engage users, making the self-tracking experience more meaningful. However, potential biases and limitations should be considered to ensure an accurate and objective self-tracking process. The study aims to examine users' interactions with visualized data in the digital self-tracking process and understand their perceptions of the accuracy and objectivity of personal data visualizations and the self-tracking processes on platforms that offer self-tracking features. These platforms include applications for tracking health and fitness, habits, music listening, book reading, and movie watching. The study employs a qualitative approach using semi-structured interviews with an ethnographic approach as a data collection method. This approach was selected to investigate users' interactions and opinions on data visualizations and the digital self-tracking process.  The findings show that participants primarily use data visualizations and other personal visualizations as reminders, for comparisons, planning, and motivation. Although they do not extensively analyze the visualized data, participants report experiencing heightened self-awareness and motivation. Despite their awareness of potential inaccuracies and subjectivity in the visualizations and the self-tracking process, participants are willing to overlook these aspects due to the perceived benefits associated with the process. Moreover, participants generally express a level of trust in the accuracy of their visualized data.