Jesus told Peter earlier that He will build His church upon Peter and the gates of hell can't prevail. - That was Peter's purpose.

Now Jesus died and Peter returned to his profession - Fishing and he caught nothing. vs 3

If you pursue ambition at the expense of purpose, it will lead to nothingness and frustration..

Anything outside the plan of God for your life will be laborious and frustrating.

Pursue God's plan for your life