I went to my first Songkran thinking it was just one giant water fight. I left that day understanding exactly why my mother-in-law made me kneel in front of her.

I'm British, 33, and I'd been with Fai, 29, for eight months when my first Songkran came around. She'd warned me, laughing, that April would be "a whole week of people throwing water at you for no reason," but nothing she said fully prepared me for what it actually was.

The first day we spent on the main street of her neighbourhood, soaked head to toe from ten in the morning, water guns, buckets, and an improvised hose a neighbour had rigged up to the garden tap. It was chaotic, loud, and honestly one of the most fun days I can remember in years.

On the second day, Fai woke me up early and told me this one wasn't for the street. We were going to her grandparents' house, in a village outside the city, and she asked me to wear something proper, nothing that could get soaked.

We arrived mid-morning. The house was full of aunts, cousins, and neighbours, all with the same solemn calm that contrasted sharply with the chaos of the day before. Fai explained on the drive over that we'd be doing "rod nam dam hua" — pouring scented water over the grandparents' hands to ask for their blessing.

When my turn came, Fai led me over to where her grandmother sat, a tiny woman well past eighty who'd spent the whole morning greeting family with the same endless patience. I knelt, following Fai's whispered instructions, and poured water with floating flowers slowly over her open hands.

Her grandmother said something in Thai, long, eyes closed, which Fai translated later in the car on the way back: a blessing that I'd take good care of her granddaughter, that I'd work honestly, and that I'd come back every year to do the same. I didn't understand a single word in the moment, but I understood exactly what was happening.

I asked Fai that night why she hadn't warned me how different that moment would be from the water fight the day before. She said Songkran had always been both things for her, since she was a kid — chaos with friends in the morning, calm with family in the afternoon — and she'd figured I'd understand it just by living it, not by having it explained beforehand.

She was right. A year later I knelt in front of the same grandmother again, this time knowing exactly what every gesture meant, and that second time, when her blessing ended, she held my hand a second longer than she needed to.