Unless there’s a huge universe shattering event that cannot be corrected easily with use of the tools and resources at hand, Timelords cannot travel back into their own time stream and give themselves advice. There are exceptions; The most recent example, the 10th Doctor and the 5th Doctor, (although we saw the consequences of that one, the Doctor marrying his daughter) and the 11th Doctor hopping back 12 minutes to speak to himself.
Though I pretend to be a Timelord on television, unfortunately or fortunately, I cannot go back in time to speak to my younger self, to give guidance. But this is a fun place, a place to ponder the imponderable question… so what if?
17 was an idyllic time for me. Senior year of high school, life changing events occurring, going off to live in California for the summer. I don’t think I would like to give my 17-year-old self any advice, and certainly, he would not listen to me. He was a know-it-all with very little room for receiving advice. He would have looked at me and wondered who I am, I’d have to lie and say that I was a distant cousin from India, or face a paradox that might rip a hole in the fabric of space-time the size of Topeka or the point of a needle, quantum mechanics can be so tricky.
So after the awkward introduction, there’s only one thing I would say. I’d ask him just one question.