I am 28; I have an undergraduate degree in a field outside of the hard sciences, but I want to now work towards securing a job as a researcher - hopefully, in the field of drug creation and discovery.

My question: am I too old? Given the fact that it will probably take me 8+ years to get through university again and secure my PhD, is 36-39 too old to start a career as a scientific researcher? Follow up question: does this really matter if I love the subject? Hypothetically, if all else somehow went to shit, I think I'd rather be homeless with a PhD in a science that I loved than homeless with an undergraduate degree in a humanities based subject that always felt like more of a hobby.