You have to treat "Helping Other People Succeed" as iterated prisoners dilemma. The tit-for-tat strategy seems best in the real world. If you help and they defect, you have to defect in response. IE don't let them continue to take advantage of you. But you should cooperate first round.
Helping other people succeed guarantees nothing for you - people can be selfish - especially in business
Since romantic relationships are often an important aspect of one's life, I would also add: If you're interested in someone go talk to them.