Confused about using the plural

There was a time when *thou *was used for the singular and *you *or *ye *for the plural.

I have more of a problem with the first person plural. Does “we” include or exclude “you”? Most of the time one can infer from context, but sometimes it can be troublingly ambiguous.

The second is wrong because we all have only one left leg.

The second is clumsy and incorrect. Better to say - Ones body~

Or even “your body.” It depends on the tone you’re going for. “One” is a bit impersonal and, IMHO, a little stiff-sounding. “You/your” is a bit more personal/relaxed.

Depends on who you are asking. Some folks would say the correct version is:

Our bodies are not evolved to sit in front of computers all day.