What's also interesting about him and his career was the almost universal respect he had in the NFL, even among fans of rival teams, and among the Patsfans fan base when he played for the Chargers and Dolphins.
Suicide is an irrational action that we will never be able to find a rational explanation for.
It makes no sense to us but in Seau's mind, he likely felt his actions were rational and in the best interest of his loved ones... Perhaps thinking about a life insurance payout or just the thought they were better off without him, especially if he felt he was becoming increasingly irrational and dangerous as has been the case with others who had numerous concussions.
Sadly we will never know.