Pack Challenge

One thing I learned about travel is pack a third of what I need. When I was in Euope for over three months I packed an oversize/ normal suitcase and a carry-on.
However, I still packed too much. I used maybe a third and lost many things jumping around Europe.
Less is more, just pack essentials. For instance,  winter is harder to pack since everything is bulky, thus my luggage was huge. So on this mini trip  to Colorado, Washington and California ,I test the bag theory.
The struggle is the weather changes. In Colorado it is hot and cold very confusing weather. Washington state is damp, and cold then California is sunny with a chance of cool air.
I packed two pants dark marron red and black. So far I have worn the black countless times. Packed three sweaters, grey, yellow and a blue/cream stripe. I sweat easy so I rotate them and either wash the arms or febreeze if no time. Pack countless underwear, a few socks, pjs that can be yoga clothes  light shirts for layering,  heels, boots with a heel that go with everything, one skirt and a black dress plus essential  products and my Toshiba. All in a carry-on case and a duffel, so I have nothing to check.
So far my experiment is good, Rick Steve would be proud. Yet, I feel that I packed too much still. For an adventurous traveler light, quick and spontaneity is key for new opportunities. This is the traveler I am working at being: light case, yet the right essentials for every possible occasion. It is temping for me to spend (which I do) so by learning to pack a third of what I need would be smarter.  I have a week left and hope I can do it.