How long is too long to wait for marriage?

So I personally think 2 years is a good amount of time to get to know someone and “know” that you want to marry that person. My current bf told me he thinks 4-5 years is a good amount. That honestly triggered me because I was in a 4 year long relationship with my ex and at the tail end of that relationship after we broke up he told me he knew he didn’t want to marry me early on but didn’t want to break up because he did have love for me etc.

At the time with my ex i knew 2 years was my max but we were in college so I understood we couldn’t and was okay to wait.

With my current bf I guess I’m just afraid of that happening again. In general I’m just afraid of someone pretending to be in love with me and I give my unfiltered love just for someone to waste my time and genuine energy.

My bf is in his doctorate program which by year 4-5 he’d be finished and fully established in his career so maybe that’s why he also said 4-5 years. His parents pretty much pay for all his living expenses. He has no job to focus on school which he definitely does. Next year he’ll have his internship that’s out of state that he has told me he’d love for me to come with him. He knows it’s a lot to ask of me but if the time is right and I want to that he’d love that I come with him.

So idk if it’s unfair and crazy of me to say that 2 years is my max when he’s still in school. But at the same time I hear men making it work for who they love….

So idk, I guess all I can do is trust and communicate what I’m expecting more clearly? I’d just hate to be hurt like I was in the past, have my time wasted and end up dating in my 30s which I hear isn’t fun lol.

Any advice or thoughts I’d appreciate it!