Student pilot reported while holding short of runway; ATC instructed them to hold short of runway but mistakenly interpreted the instruction to hold short on the runway. The pilot taxied onto the runway and caused another aircraft to go around.

Narrative

Problem After vacating Runway 4 at Taxiway C; I contacted VRB Ground and was given clearance to taxi via A back to Runway 4. I held short of Runway 4 and switched to the VRB Tower frequency. The Tower contacted me on the frequency; and I informed them that I was performing my pre-departure checks. Shortly after; the tower instructed me to 'hold short of Runway 4;' to which I correctly read back the instruction to hold short. However; during my pre-departure checks; I mistakenly interpreted the instruction as 'hold short on the Runway;' due to a lapse in attention caused by my focus on the checklist. As a result; I taxied onto Runway 4; positioning my aircraft to leave as little Runway behind me as possible. I then heard Aircraft Y initiating a go around. The Tower immediately contacted me; informing me that I had entered an active Runway. Due to confirmation bias and my belief that I had been cleared onto Runway 4; I responded that I had complied with the clearance; which in fact was a mistake. I assumed that I was cleared to 'line up and wait' based on previous experience. Having recently performed this action during my last circuit; I misinterpreted the 'hold short' instruction to mean the same; leading to the incorrect taxi onto the Runway. I genuinely believed I had followed the correct procedure until ATC informed me of the runway incursion. Only after reviewing the situation in my head did I realize I had misunderstood the instruction. Over the course of 8 flights out of the last 9 at VRB; I had completed more than 30 takeoffs and landings. This repetition may have led me to lower my guard and rely too heavily on my recent experience; reducing my overall vigilance. While performing pre-departure checks; I was instructed to 'hold short' of the position I was already holding. In my distraction; I mistook this for a 'line up and wait' clearance. Though I correctly read back the instruction; I didn't process its meaning; which caused a temporary lapse in situational awareness. The rushed feeling to complete my checklist also contributed to this error. After Aircraft Y initiated a go-around; the Tower Controller contacted me; at which point I realized my mistake. I promptly exited the Runway at Taxiway A1 as instructed; contacted Ground and taxied back to the ramp to debrief. I have a meeting scheduled with Person A and Person B of my flight school to discuss preventative measures and undergo additional ATC; runway safety training and circuit training. I signed up for a 'Runway Safety' webinar to gain further insight into these types of incidents and learn strategies to avoid them in the future. I will review the Human Performance Limitations chapters from my ground school textbooks to refresh my understanding of how to recognize and mitigate cognitive biases and human factors that could lead to similar incidents. If possible; I plan to visit the VRB Tower and speak directly with the controllers to gain their perspective on the incident and better understand the impact and handling of such situations from their side. I will develop an Action Plan specifically for the pre-departure phase of flight. This will include completing the pre-departure checklist in the run-up area; ensuring that when I reach the Runway threshold; my primary focus will be on ATC instructions and situational awareness; minimizing distractions during critical moments. Additionally; I will treat each circuit as an individual flight; carefully analyzing and critiquing any mistakes to ensure continuous improvement.