I was first aware of it in 2009. Forgot completely. Became dimly aware again in 2011. Did nothing. Got rolling properly in mid 2013. I feverishly read up on it for a couple of weeks. Looked up Gox, thought 'this is the NASDAQ of Bitcoin? Fuck that' and went to localbitcoins.
Almost all of the 'opportunities' and businesses looked like blatant scams to me and time proved it to be correct. I've learnt vast amounts of new stuff along the way.
Similar stuff. I found out about bitcoin in 2010, decided it was a neat idea but had no potential, and went on with my life. The late 2014/2015s roll around and I find myself realizing that the price is now in the hundreds. Definitely one of the things I regret the most, but I'm still happy that I got in the game relatively quickly.