Why it is important to use dry firewood and firewood only?

This video shows how flammable may be ovens and stoves inside surface which are covered with soot when burning wet wood or other materials that kind of burn, but are not meant to be burned in domestic stoves. Soot sticks inside fireplaces and chimneys and may catch fire from spark.
Best firewood is pine, spruce, birch, alder, aspen, oak, ash. Firewood are cut into length that fit into oven/stove and then split into pieces. Then it is good to dry wood outside about one year, bark side up, after that bark side down in a shed also one year. Before burning it's better to bring wood indoors day or two before using them. That way wood can dry more and adjust to indoor rooms climate and humidity. Always light firewood from above not under and use clean paper or smaller pieces of wood to light a fire.
That stove was built in 1993 and since then we burned different kinds of wood, including dry and wet firewood, sticks and small branches directly from forest, wood that were covered with some paint, paper, laminated paper, packages and so on.