I was usually the guy looking for synergy and combos in my play group in high school, so I don't remember much that really got in my way besides being beaten out by aggro. That being said, I distinctly remember the first time I ever got an infinite combo played against me. The problem was, the guy I was playing dropped a few cards on the board and started rattling off what he could do and then scooped up the cards. I was too shy then to ask for clarification as to what just happened, so I have no idea what the deck actually did. I know it was simic and since it was in 2004, maybe 2005, can't use any more recent cards. I'm pretty sure that there was a cephalid involved and the combo resulted in all my stuff getting tapped every turn so I couldn't ever actually do anything. Any ideas what that could have been?
I do know that since then, I'm always a little more careful to explain combos to new players, sometimes even before we start playing so they understand what's going on in the game. I really felt lost and frustrated that day, and I'd rather use my combos to inspire and show just how interesting this game can be, not as a tool to shut people out.