I've been dying my hair black since my early 20s. I don't know what I was missing in my diet or if it was all the stress of being zen but I've had grey hairs for as long as I can remember. That said, I have a terrible memory and can't remember much about most things including university even though I'm still paying off that debt - good one, brain, you waste of money; high school; and childhood. I do remember having grey hairs in early high school though so I may have had them in primary school and only noticed once I hit puberty and self-consciousness in high school.

I used to have bright red hair back in the day which was a high cost, high maintenance time in my life. These days I dye my own hair using a supermarket dye because black is easy peasy; it's an all over even colour, and very low maintenance.

I swim 2-3 times each week and chlorine dries my hair out something awful so I need a hair dye that is gentle enough not to wreak havoc on my already damaged head. Schwarzkopf Perfect Mousse is the gentlest permanent dye I've found. I've been using the black 1-0 shade every 5-6 weeks for years and have had no issues with it. I am a messy person due to clumsiness so I have accidentally dyed things that aren't my hair using regular dye pastes. The foam is super easy to apply and manage, and if you do manage to get it somewhere it's not supposed to be (like a bathroom wall) because it's gentle, you have time to wash it away without staining.

Chemist Warehouse has them for $8.99 ($6 less than the RRP). Bargain!