Now being greedy is something that you should always avoid because in gambling, its hard to get the same winning result so if you are able to have the profit better to get your capital out and secure some profit before you gamble again or you can just totally leave and enjoy your whole profit.
I wouldn't called that as a greedy act but there are gamblers who just wants to tried their luck more. Others are able to get a win more while unfortunately, there are others who are not able to control themselves and at the end, their whole bankroll plus winnings were lose.
For sure if you feel the same luck when doing gambling, you will try even more to play and won't stop because you feel lucky at that time.
It's now on your own actions if you will get out immediately after a big win or you will try your luck for more rolls since you are lucky.