Since the dawn of Youtube, patient, creative types have been going viral with their time-lapse videos, showing us how much they (or their dogs) have changed by taking periodic videos or photos and editing them all together. But none have had the power to make us cry like Dutch artist Frans Hofmeester's videos of his 20-year-old daughter, Lotte, and 17-year-old son, Vince, whom he has filmed every week of their lives.

Back in 2012, Hofmeester went viral with "Time Lapse Lotte," which compiled the weekly videos he had shot of his daughter from a few days after she was born until she turned 12. In all of the scenes, she's talking to the camera in front of a simple white backdrop, making it all the more obvious how much she changes and grows from week to week. The video was so powerful, Sprint bought it to use in an American commercial that year.

Portrait of Lotte, 0 to 20 years www.youtube.com

"When Lotte was born, she was changing at such a rapid pace, and I was desperate to keep the memories intact," Hofmeester wrote in an essay for The Guardian after gaining fame. "As any parent knows, the difference between a child at two days old and two months old is startling."

It turns out, it's still startling to see someone age from age 12 to age 20. The latest "Portrait of Lotte" takes her into adulthood, and it already has 5.5 million views since it went live a few weeks ago. As we see her teenage emotions and style changes, it's like undergoing adolescence all over again. For some of us, it also feels like a glimpse into the future, when our kids are teens, too. The video loses none of its tenderness in the later clips. As viewers, just like as parents, we're constantly nostalgic for the previous second of footage.

Hofmeester has been filming his younger son Vince, as well. The teenage boy's video isn't quite as poignant as his sister's, maybe because of the difference in their on-camera personalities. Vince is a bit more of a ham, and the music that accompanies his footage is more upbeat.

"Lotte's video has been viewed more than Vince's, probably because she is a girl, because she's older, female," Hofmeester wrote in the Guardian. "There is more scrutiny of girls. Her video is very sweet. Vince's is more playful, he's pulling faces, sticking his tongue out, being this cute little boy who won't do what daddy says when he's in front of the camera. I love it."

Immediately upon seeing both videos, some of us might regret not having done the same for our own kids. As the success of Lotte's latest video shows us, though, it's not too late to start.