The answer is in Judges 14:4 and in Judges 15:11.
[Samson's] father and his mother knew not that it was of the Lord that he sought an occasion against the Philistines - for at that time the Philistines had dominion over Israel. Judges 14:4 [KJV].
Knowest thou not that the Philistines are rulers over us ? What is this that thou hast done unto us ? Judges 15:11 [KJV].
Samson, alone, was resisting the occupying force. All that he did, he did alone, as moved of the Spirit of the Lord. "And the Spirit of the Lord came mightily upon him and he rent him [...]" Judges 14:6.
Samson's activity was clandestine for Israel was quietly accepting the dominion of the occupying force. At times, Israel was warned that they would be judged and warned not to resist, as happened, for example, in the days of Jeremiah.
But not so in Judges. Joshua had led them into the land and had apportioned the whole of Canaan for Israel to dwell in, safely and securely. It was Israel's fault that they had not striven enough to drive out every enemy. (And thereby hangs a lesson for every one who would follow a spiritual path.)
Joshua 23: 10 to 13 demonstrates what was set before Israel at that time. "One man of you shall chase a thousand" ... "If you do in any wise go back - they shall be snares and traps to you ..."
So Samson kept things close to his chest and told not even his parents of his secrets. But even such a warrior as Samson was tempted by a woman. And it was the very woman by whom he was actively seeking an occasion to rub up against the Philistines and erode their position of power, Judges 14:4.
Even she by whom he was inveigling himself among the Philistines became the source of his (temporary) downfall.
And what a lesson that is to every one who would walk a spiritual path. "Keep the doors of thy mouth from her that lieth in thy bosom" says Micah in 7:5.
Trust only in the Lord, especially in times when all around acquiesce to nature and the flesh in spiritual things.
As is done this very day.