Why are you so surprised by that? It's not terribly uncommon for those of us that have been long time Tibetan Buddhist practitioners that met the Dharma at an early age
Most of my friends who ended up studying Buddhism in India or learning the Tibetan language or studying Buddhism full time first connected with Tibetan Buddhism in their teenage years. In the Rinchen Zangpo Tibetan Course I did in Dharamsala, I would say over half the people attending were connected with Buddhism since their teens or early twenties. In my own case, I connected with my first Tibetan teachers when I was around 14 or so- but I say CONNECTED, that doesn't mean I was practicing all that seriously. It also took me awhile to find the teachers who were the right "fit" for me- often it isn't necessarily the lama living in our locality.
Do I think that necessarily means I was Tibetan in my last life? No. But one of my teachers insisted that those who learn the Tibetan language effectively would have to have some kind of special imprint from ONE of their previous lifetimes, as most Westerners who try to study it place it on the backburner relatively quickly.
Do I think this makes me a special pants? Definitely not. I have not done enough to try to actualize the dharma in my current lifetime so it doesn't really matter much whether I was a Tibetan Yak herder or a Gaudiya Vaishnava cowherd in my last life. (Both are possible, before meeting my first Tibetan teachers when I was 14, at 13 I was lying to my mother about going to the library when I was in actuality serving food and sweeping floors at the Toronto's Hare Krishna temple).