Another thing I've learned is that it's not what you say, but who you are when you say it. Both who you are to yourself, and who/what others perceive you to be when you're saying it.
You could say something to your past self that would verify your identity in an attempt to make your words carry more weight, but I don't think there is much you can do to convince a past self that you were not a figment of their imagination.
I laughed when you mentioned people not taking advice only to later take the advice but believe they came up with it themselves. It's really annoying when it happens to me, but I've certainly done it myself. I'm not sure why it happens that way exactly, but I try to be aware of it at least and always try to be very gracious for anyone taking the time to offer advice in the first place, whether I take it or not. And later on, when I end up taking the advice anyway, I really do try my best to not believe I came up with it myself.
Take the list posted here. It could be terrible advice to a different start-up founder with similar goals if that person already knows how to code, and is working on a product that is more complicated than a 2 week prototype can cover.
But if when FamousPersonX suggests that "you should be networking more, getting feedback, and iterating on smaller offerings of functionality while expanding your network of interested customers", somehow that's revelation from on high, and how insightful that is, and wow... no wonder they're a huge success, etc.
Doesn't even actually mean the people in question follow the advice (generally they don't) but the reaction is annoying.
So that brings us to the following thought: There are two kinds of advice a time traveler can give: (i) "Objective" stuff that will actually happen, and that perhaps you can provide proof for, i.e. the Instagram advice; and (ii) "subjective" stuff that may or may not turn out that way, i.e. "don't marry that girl".
BTW, due to the Butterfly Effect (http://en.wikipedia.org/wiki/Butterfly_effect) these two are not as clear cut as above.
Either way, dwelling negatively on the past does not help as you cannot change it. I don't believe I would have come to the same conclusions if I had not experienced it first hand. Remember: work smarter, harder not longer!
my favourite high level advice is: the best time to plant a tree was 5 years ago, the second best time is today.
I started out on my own startup path almost 2 years ago now, and it's dawned on me by now that things don't change. If you're building a company (or anything worth building really), you will always have problems, they will often catch you by surprise, and imminent success or failure always seems like it's right around the corner.
Best case scenario, you get to deal with higher quality problems, make more money, and still love what you do. Worst case... well, I guess you go get a job (and/or go bankrupt?)
Hindsight is always 20/20...
