My old man had a friend like this who worked with him, he wasnt suicidal either he was a normal guy but he said exactly the same thing as your saying.. and a few years later he actualy jumped off a bridge onto the Busy M25 that goes arround london, he tried to take his life, but when asked why he did it he said he didnt actualy remember a thing like no memmory of it, yet he didnt hit his head or anything so thats just completely weird.

A few months later he did it again and this time jumped off of Tower bridge (this is usualy where most people end there life its a hotspot for it now)
The thing is he didnt hurt himself at all apart from a graze, yet again he didnt remember a thing.. I dont know what to make of this at all, but the guy acts completely normal and he has said exactly the same thing although he isnt suicidal so yeah.. i had to reply to this post seeing as its just ironic that my dad knows someone in the same possition.

Also i will add that a week later he went beserk because he got Tinnitus (high pitch ringing in the ear) which medical services still cant propely identify the cause of, this led to him having a nervous breakdown.. So overall a very strange occourance for someone who was normal one minute and just gone the next. He also had no history of mental illness in the family.. so again "weird"