Or, it could be argued, the problem is that some people get too greedy!
I tend to be more conservative when betting, and I do it only for fun, or rather, to keep myself interested and to alleviate boredom. I'm not sure "fun" is really an accurate characterization.
Anyway, if you lose 15 units on each of the two losses and you win 55 units, you'd be up 25 units at the end of the season. That's pretty good if you ask me. Even if you lose 25 units on each of the two losses, you'd still be up 5 units at the end of the year. Since I don't rely on gambling for income, any positive result at the end of the season is satisfactory to me. I just don't want to come out in the red when it's all over.
The trick you said
was never play the game too long
A gambler's share
The only risk that you would take
the only loss you could forsake
The only bluff you couldn't fake
Don't get greedy. That's when people get hurt and do stupid shit like gambling away next month's rent or mortgage payment. Just my opinion.