I can't believe how many times I'll spend a ton of time working out my strategy, planning and mapping out my future moves and contingencies, only to find out that once the clash begins, I've miscounted the holes or inadvertently given myself an extra move during planning that I, of course, don't get when the game is played. 

Playing Mark is especially hard since he's like a computer and almost never seems to make a mistake.  I try to get inside my opponent's head and figure out his best move or moves; but in doing so, it's easy to lose track of turns as you imagine yourself, switching back and forth between players.  I've done it several times where I've lost track and where it should be my opponent's move, I think it's mine.  Then I'm crushed when I realize it's not going to play out the way I think it was.

Arggh!

Also, shouldn't play with my Thinkpad's touchpad pointer.  Twice I've inadvertently placed a peg because I barely tapped while hovering over a considered move.  Not that it mattered in either case since I was on my heels already.  Just sealed my fate a little sooner.

Drives me crazy when I'm confident that I've got my opponent on the run and feel like I'm predicting/forcing his every move or at least have a solid response to anything he can try, and then he crushes me with something I hadn't seen.  And I'm left wondering "how did I miss that?" 

It wouldn't be so bad if I wasn't so sure of myself while waiting for him to play his turn.  But to go from the smell of victory to defeat in such short order...ACK!!

If I'm going to keep doing this, I really should get a physical board.  My brain gets scrambled when I'm trying to look at the screen and mentally map out where the battle is or might be going.  I've gone through a lot of graph paper, but I don't "see" the board as well on a grid.  Even if I just had paper with dots on it, that'd be okay.  I guess I could make one and just print it out and make my own stack of TwixT scratch paper.

I'd still like to have a real board though.

Why does it always seem that my complex of pegs and links never seem to match up well, while Mark's seem to line up perfectly? 

One last one (for now). 

I've been schooled by Mark so many times, I'm gun shy.  As I posted above, on numerous occasions I'll think I'm gaining the upper hand, only to have Mark lower the boom and show me how foolish I was to have hope. 

But what this does is that when I have found myself in a strong position, and Mark lays down a move that seems to be exactly what I want him to do, I get nervous.  "What's he up to? What's he planning that I'm not seeing?"  Sometimes that'll get me to over-think and maybe pass up the right move to address some other threat that maybe isn't really there.