I have always felt that people who don't really understand marketing have problems grappling with a few of the important concepts that should form the basis for everything that you do in marketing.
At the same time, being 35 years old and unmarried has also taught me about the importance of understanding these same concepts.
You need to manage expectations
In marketing, it is important to understand the expectations of your potential customer and either meet or exceed them. You never want to promise something to your customers and fail to deliver it.
The 35 year old bachelor needs to make sure that his mother doesn't think he's going to marry every girl that he dates. Every girl that you meet doesn't need to think you're going to marry her. That not to say that you shouldn't treat a woman well, it's just that you have to manage expectations properly if you plan on developing any sort of trust, which is key to every relationship you will ever have.
You need to know who you are and why you are special
As a marketer, you need to know what your brand is, what it stands for and what your unique selling proposition(USP) is. You need to be constantly working to refine your USP is and how you communicate it but you should never lose sight of it and you should be communicating it as often as possible.
The 35 year old unmarried bachelor needs to know who he is, what he stands for and why he is special because you need to believe in yourself and what you're doing in order to feel like you are truly worth spending the rest of your life with.