过去无法改变未来无法实现
[guò qù wú fă găi biàn wèi lái wú fă shí xiàn]
'The past can't be changed; the future isn't achievable' conveys a pessimistic or disappointed state of mind. The user may feel trapped by previous decisions or regret and believes the desired outcome in the future will not come true, indicating helplessness or disillusionment.