Charlton made a strong start to their Championship campaign by beating Derby and securing an away win against West Ham.
However, they faced a difficult night in north London, suffering heavy damage after conceding two goals in the final minutes of the first half.
Speaking to BBC Radio London, Mesik emphasized that testing themselves against Premier League teams is a dream and offers great learning opportunities.
The task became even harder when central defenders Collins Sichenje and Billy Koumetio were forced off with injuries after just 15 minutes, forcing a tactical change.
