In my 20s. Heard about BTC very early (sub $1), but being the lazy idiot I am, I thought to myself I'd do some research on it later, but it never happened and forgot about it. I later heard about it again in early 2013 and was surprised to heard it was at like $10, followed by $20 some time later, and finally shocked to heard the heights it got to in april. Again, being the idiot I am, I still didn't invest anything in it thinking I had already missed the train. I finally got into it when I heard about the SR bust and I've already managed to make a nice profit. I'll never forgive myself for not getting into it earlier, though.