As a culture we don't talk about this a lot, but what happens when you're jealous of your partner? Not jealous in the traditional sense, but wanting to feel as successful as your partner — say financially, or career-wise.
It can be hard to handle it when your partner is doing better than you in a certain way, because while you want to be happy for them, you may also wish you had that great job, opportunity, money boost, etc. As a man, this may hit extra-hard if you feel like you "should" be the one to contribute more financially. (What if she makes more than you?)
The fact is, if you're in a long-term relationship, each of you is going to go through different seasons in life. Sometimes one of you will be up, and the other will be down in a certain area. So whether you're dating or in a long-term relationship, this dynamic is worth exploring. Believe it or not, it can actually bring the two of you closer together if you remain awake, aware, and are willing to engage in conscious dialogue.