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.
Excessively Long Feedings. During the first few day of breastfeeding, it's not uncommon for a baby to nurse for longer periods of time, or to nurse very frequently. However, by the 5th day, your milk supply should increase and your child should be able to get all the breast milk he needs within 45 minutes. If your baby is actively sucking at your breast for over 45 minutes at each feeding, it could mean that he is not getting enough milk.