Tippie said:
This is a really common fault with winter gloves. My expensive Dainese ones are utterly pox in this regard, good and warm, waterproof from the outside, but water runs down your wrists into them on any long wet ride or even if your hands are just damp.
A couple of years ago I finally updated my textile riding gear with a head-to-toe Goretex setup (boots, pants, jacket, gloves) from HELD, a German brand mostly known for their gloves but also making good leather and textile suits etc. HELD were a nice option for me, given that I'm 'differently able in the vertical plane' and they make different fits so I can actually wear stuff off the peg. On a rare day of heavy rain I decided to take the Corsa out for a run to see how they did, everything all good except very wet hands. All I had ever known was to wear the gloves outside the jacket since by logic the rain gets blown up an open sleeve when your hands are facing forward.
With wet hands from a well reputed and guaranteed waterproof set of gloves, I contacted the AU reseller and it turned out I had two problems. First was that one of the gloves did indeed leak a small amount - tested by simply hanging the gloves over a sink and filling them with water. Next day one was still full and the other some way down.
But the main problem was that they asked if I wore the gloves outside or inside the jacket sleeve -"outside" I naturally answered. Wrong. Far more water runs down your arms and into your gloves than blows up the small gap in your sleeves. Always wear the gloves inside the jacket.
I got a replacement pair of gloves and tested them - both remained full of water overnight as did the lightweight goretex summer gloves I had bought from them also. Next opportunity I went riding with new gloves inside the jacket sleeve and what would you know but both hands stayed perfectly dry. Forty bloody years riding bikes and I hadn't worked that out - my defence is I live on a dry continent!

Even more obviously the same applies to boots, but I had at least worked that one out. But in a similar vein, I always used to wear boots outside of leather pants. From my recollection, Valentino Rossi was the first guy I remember wearing leathers outside of boots. He clearly didn't do it just for reasons of rain, but interesting all the same. My old leather Oz-made PEELS suit (which shrunk in the cupboard) was tailored to fit and the cuffs of both sleeves and pants would only fit inside boots/gloves. In light rain not enough to stop and put on an oversuit, I would run the pant sleeves unzipped around the outside of my boots and stay mostly dry. In terms of gloves I probably just never had anything decent enough to expect them to not leak, so wet hands was considered normal.