Origin of thalweg. German Talweg, Thalweg : Tal, Thal, valley (from Middle High German tal, from Old High German) + Weg, way (from Middle High German wec, weg, from Old High German weg; see wegh- in Indo-European roots).
Besides as Sandra said the natural age of weaning is older than 2 and the WHO advises breastfeeding for a minimum of 2 years. It is not ridiculous that your son wants milk at 22 months. I fed my oldest child until 2.5 and am still feeding my 18 month old and plan to keep going as long as I can.
If you choose, you can offer diluted fruit juices (1 part juice to 10 parts water) but avoid soda and other sugary drinks. Once they turn 12 months old, you may still be breastfeeding but you can introduce full fat cow's milk, or even pasteurized goat's and sheep's milk if you're feeling adventurous.