"I, for one, don't know "

for one is an interesting idiom. It is used in several ways, predominantly to say that you believe your opinion or action is right, even if others do not

The rest of you may disagree, but I, for one, think we should proceed with the plan.

It can also indicate a particular one of several possibilities

I, for one, am not upset or ashamed; in fact, I feel very grateful.

or, as one example, even if the only one

And I, for one, welcome our new insect overlords!

This last use (first uttered in The Simpsons) has become mimetic, and was used to honor Watson, IBM's artificially intelligent computer system capable of answering questions posed in natural language.

I have a slightly different answer, and this is supported by the Oxford Advanced Learner's Dictionary:

for one:
used to emphasize that a particular person does something and that you believe other people do too.

• I, for one, would prefer to postpone the meeting.

(Many people would like to postpone the meeting--and that includes me.)

I, for one, means that I am speaking only for myself and sharing my view of something even if that is contrasting from other's idea.

"I for one" is used to stress an individual's specified view about himself.

Eg: I for one, don't think it is a good idea.

This is reworded as

"I don't think it's a good idea, but other may think it is."

A comment I read on a social network site,

"Based on what I have learnt about science, the light from the closest stars take thousands of years to reach us, a star doesn't die in a couple days, which means I would have to look through a telescope for a VERY long time to witness the death of a star LIVE. Looking at a CGI version of it is fine, I don't have a problem with that, but should it be portrayed as though a star is dying as I type this or died recently and this is a video recording of the event? I for one don't think so."