If I had to do poker over again,...
I'd get a screen name that was first alphabetically - would've saved me a lot of time scrolling during tournaments - every minute counts at the tables.
I would've spent more time on the business application side of poker. The apps that were built and made the most money were technically easy to build and actually many players had the ideas before they were built. It was just the first person that was willing to leave the tables and build it got the rewards.
I'd spend more time practicing reading hands and reading tells. Strategy and math are great and necessary, but so is being able to read opposing players.
I'd spend less time at the penny tables thinking that $2 was a lot of money. It is all relative. I'd spend $10 on lunch on a daily basis but would be unwilling to put a decent amount of money online without earning it from other players. On one hand, I think the time and frustration spent playing micro-stakes helped me. On the other hand, I think the time spent hindered me from moving up faster.
What would you do differently if you started over?