Is variance just another word for gambling?

Okay. I get it. Just because I’m 50/50 in a hand, doesn’t mean that if I play it 100 times, I’ll win 50% of the time. But how many hundreds of times would I have to play to come close to 50%?  500, 600? Even when I played online, I never tracked that. It seems to me that my aces, say, lose more than 15% of the time vs. one person.  So, when things don’t work as statistically expected (i.e. vary from the norm creating variance), might there be other reasons? 

 Did I not bet enough pre and let too many people see the flop?

Did I not bet enough on the flop or turn and let them get there?

 Should I have stayed home?

 Guess I’m basically wondering, when people say,  “get it in good and you’ll profit in the long run”, just how long is the long run?