I know when you first drop a part into a new assembly there are two (maybe more) ways to align the 1st part's origin to the assembly's origin.

• Without clicking in the drawing area click the eye and engage the origin button and drag the 1st part, still attached to the pointer, to the origin and left click.  The origins will coincide and the assembly process can begin.
• With the 1st part in the drawing area you click the green check in the top right and it'll automatically coincide the two origins.

What I'm asking about is if you're acting the damn fool and you rotate or move the first part around the drawing area and you then need to link them again.  The part is sitting all catawampus in the drawing area and resisting the aligning process.