Judges 13-15: Something borrowed, something... red?

(Today's passage covers Samson's birth, his marriage, and his early conflicts against the Philistines.)

I remember stories about Samson: strong, brave, mighty. What I don't remember from the stories is that Samson was a blood-thirsty nutcase.

In Judg. 14-15, we read about Samson's early conflicts with the Philistines. A brief recap, for those who missed it:

The Philistines have conquered Israel because they were misbehaving (again). Samson, a Nazarite, decides to take a Philistine wife from Timnath, despite the protests of his parents. (Judg. 14:2-4) At the wedding, Samson poses the thirty guests a riddle, with the prize being thirty sets of clothing. He gives them one week. At the end of the week, the thirty guests still haven't figured out the solution to the riddle, so they get Samson's new wife to get it for them. (Judg. 14:11-17)

Samson accuses them of sleeping with his wife, but a deal's a deal. He goes down to Ashkelon, another Philistine city, kills thirty of them, takes their clothes, and gives it to his wedding guests. Then he leaves. (Judg. 14:18-20)

Given that Samson accused his thirty wedding guests of sleeping with his wife and left, his father-in-law gives the bride to someone else (one of the wedding guests, actually). So when Samson comes back in Judg. 15 with a nice goat for his wife, his father-in-law tells him the situation. In fairness, he offers his prettier, younger daughter to be Samson's wife, but Samson will have none of it. This is his wife, even if he doesn't like her, and he is outraged that she's been given to someone else. (Judg. 15:1-2)

In revenge, Samson gets three hundred foxes, ties brands to their tails, and lets them loose in the cornfields, vineyards, and olive orchards, effectively destroying all the Philistines' crops. (Judg. 15:3-5)

The Philistines are understandably worried. When they find out that Samson was the perpetrator, and it was because his wife was unfaithful, they took the reasonable precaution of burning the wife and father-in-law to death. (Judg. 15:6) Problem solved, right? No more adulterous wife.

No. Samson, the very same man who hated his wife, left her, and burned down cornfields for her sake, suddenly decides that maybe he wanted her around after all, and kills all the Philistines who murdered her. (Judg. 15:7)

He runs away, hides for a while, and is eventually turned over to the Philistines. Whereupon he takes a donkey's jaw-bone and kills 1,000 men with it, just for good measure. (Judg. 15:8-15)

I'm having trouble figuring out Samson's motivation here. It seems like all he wants to do is kill people. It doesn't matter what they did to him, or even if they did anything at all; he just likes bloodshed. Though we haven't read about Delilah yet, I almost wonder whether Samson had it coming.