I wet the bed from potty training my mid teens. I think it developed as a coping mechanism from an early age. I remember when I was probably 4, I stole some of my little sister's diapers and used them open on the floor, so I know it's something I've had for a while. I still don't know how I thought I would get away with that...
I was probably 16 when I got my first pack by myself, I had almost entirely ceased my night wetting and of course I didn't want my parents to pay for diapers anymore because this was something that I was mature enough to handle by myself. I bought some Depends Max protection with tabs, and I didn't know they were plastic backed, something I really liked about them! Since then I have had some lapses in staying dry at night, partially due to a bad car accident. I wouldn't say it is a necessity, but I have had nights where I was glad I was wearing and one I truly regretted going without.
(I DROWNED SIRI). Wrecked my phone, which is what I get for drinking 2 liters of Mountain Dew and some adult beverages and pulling 48 hours+ awake before crashing.
So TL;DR I was 3-4 years old when it started, probably 11 when it really hit me and 16 when I truly accepted myself for it.