So I’ve been studying basic strategy like crazy and have everything memorized perfectly. I got on a trainer online and played 2,006 hands before I made 1 mistake.

So I get confident, go to the casino, started with $300 and walked away with $103. Probably played 100 hands, made 1 mistake (doubled on a soft 18 @7 instead of stand). What am I doing wrong? I even asked the dealer to point out when I made a mistake “by the book” and she said I played perfectly. I understand playing by the book doesn’t guarantee a win, it’s all just statistics- but with enough hands played, statistically, I should have at least broken even instead of down 66%. Any advice? Online I play 6-deck (like I do in Vegas), but my local casino only has single deck. What am I missing?