Jahmyr Gibbs changed his jersey number from 26 to 0 mainly because he never liked wearing 26. When he was drafted, the only numbers available to him were 26, 33, 35, or 40, so he took 26 by default. He preferred to wear his old college number 1, but since that number was already taken by a teammate, he chose 0 instead, as it was the next best option near 1. Gibbs was initially nervous about how the 0 would look on him but eventually liked it after seeing it in a video game simulation. There is no deeper or personal reason for the change other than his dislike for 26 and the opportunity for a fresh start with a number he prefers.
Additionally, the NFL's updated numbering rules now allow running backs to wear single-digit numbers like 0, which was previously uncommon, making such changes possible and more popular among players.
