Upend

How do you feel about watching the person you know best make some fundamental changes about themselves?

I’ll tell you how; weird.

You can say it depends on what they’re changing to/from, but that won’t make the weird go away. It will only add an element of positivity or negativity to the change. The common denominator is still going to be the weirdness.  It probably won’t last forever but you’ll definitely face it.  For better or worse, you’re losing part of the person you knew.