Yeah, I'm happy to clarify.

The way I understand it, "bisexual" is a very broad term that encompasses all people who are attracted to people of the same (or a similar) gender as them and also to genders different than their own. That is the "bi" in bisexual, both homo and hetero, not attraction to men and women. Under this definition, pansexuals are a specific type of bi that are attracted to people equally, regardless of gender. There are other microlabels that fit within bisexual too, some of which might better fit how I experience attraction, but this is where we get into the function of a label.

Labels exist to convey general information in a concise way, without having to explain things all the time. Under the bi umbrella, there are only two terms which the average person who's aware of the LGBT community might have heard of: bi and pan. Thus, unless you want to constantly have a definition at hand or send people to the wiki, you are heavily incentivized to use one of those terms. Having no label would be even worse, since then you would need to give a whole spiel every time you're asked. It's ultimately a pragmatic decision to use a term that more people recognize over one that might be more "technically correct."

So, constrained to either bi or pan, I think bi is the more appropriate term for me. Sometimes I feel equally attracted to all genders, but my preferences towards similar and different genders shift back and forth, often being heavily favored in one direction or the other. So I use the broader term of bisexual to encompass the full spectrum of my feelings on the matter.

Hope that helps!