'The instructor was finished But I was not finished' What had the instructor finished that douglas felt required reiinforcement - English - Deep Water

Question

'The instructor was finished But I was not finished' What had
the instructor finished that douglas felt required reiinforcement?
How did he achieve it?

Sutapa Chattaraj · Accepted Answer

Once, the author was narrowly saved from
drowning in the water So a fear crept into his heart, the fear of
drowning Afterward he takes trainer and learns swimming very well
Here, the author means that the instructor had finished his
training However, Douglas himself was not confident on whether the
fear of drowning had left him or not So, Douglas felt it needed
reinforcement
Douglas wanted to test himself So, He wanted to
try swimming in Lake Wentworth With that intention he went there
and overpowered his fear

'The instructor was finished.But I was not finished'. What had the instructor finished that douglas felt required reiinforcement? How did he achieve it?