Anybody that feels he isn't supposed to lose, or (maybe because he wasn't informed prior to his trial) is as good as someone that sells, makes expenses and profit but doesn't calculate anything to know if they're running on a loss or not.
Having known this - just as undeniable as the fact that we're all gonna die - you're always gonna lose...hence, whatever loses you incure shouldn't bother us (that is, if it bothers you). Always remember to wager only what you can afford to lose.
Everybody feels regret for any single dime spent unwisely; The difference is that it doesn't show in a rich person's emotions/countenance.
rich people have more capital that they can allocate to bet. they know how to get money back if they lose some of their money in gambling.
you may also realize that gamblers who are poor, or with small capital will bet more money they have to get bigger wins. what may make the difference is that rich gamblers understand the limits in using their money, while poor gamblers do not care about those limits. they hope to bet more and get bigger.
A small capital can still be allocated for betting. We can even play without depositing our own money as some gambling sites offer free play (demo mode) or by giving us free chips. If we are lucky we can still be able to withdraw what we win from here. Most of us sure do have a job to sustain our selves, so not only rich but even the poor gambler also knows where to get money, in case they lose the money that they allocate here in gambling.
It was actually the rich are the ones who can bet more because like you said earlier, they are able to pour more capital in the game, however this amount of money can still be within their reach. For those who are poor, them betting huge amounts of money can automatically mean that they are now betting outside their limits which is very risky already and should be avoided at all cost.
A wise gambler knows how to play gambling well. For us, we think that it was only in sports betting is the ones that we can bet a huge amount to earn a slightly huge profit but in casino games, we will only choose the high odds games (they are mostly slot games) and we can still enjoy the game by betting only tiny amounts. Once we get lucky and hit the high multipliers, or better 'jackpots' and max wins, we can still be able to profit greatly from them.