The insulation recovery during repetitive breakdowns in gas gaps is a fundamental scientific issue in both traditional and emerging electrical technology fields, which has received extensive attention over the years. This paper provides a systematic review of research methods for insulation recovery in repetitive breakdowns of gas gaps, progress made in understanding the thermal–hydrodynamic processes involved in this recovery (dissipation of deposited energy and restoration of neutral gas density), as well as the memory effect resulting from repetitive discharges and breakdowns (dominant factors and their underlying mechanisms). Based on current results, it is proposed that the insulation recovery of repetitive gas gaps breakdowns results from the synergistic effect between post-breakdown thermal-hydrodynamic processes and memory effects. This review aims to clarify the boundary and interplay between hydrodynamic processes and memory effects, as well as reveal their coupling relationship and synergistic mechanism. It also seeks to overcome barriers between related research fields, ultimately facilitating a resolution to the issue.