For everything that has to be taken to the RV before departing for a trip - 10% of the items will be forgotten, and have to be purchased on the road.
Keeping the RV stocked minimized the chances of forgetting something important.
I always kept clothes in the TT before we went full-timing. The wife didn't.
One night I had to postpone going to bed and drive her to Walmart so she could buy underwear, which she had forgotten to pack. And since it was a COE park, we had to park the truck at the gate and walk over a mile back to the campsite.
In Texas, we tend to do things differently than some places. We would stock the rig in September, and clear everything out in early June. Because late June, July and August are simply miserable for camping with daily temps over 100. We have camped every Nov, Dec, Jan, Feb and Mar since we got our first TT.