Experiences vary. Like countless other people in my generation, I spent most of the first 25 years of my life living in a house which was entirely plumbed in lead (including a long run into the house), and neither I nor anyone else living in the house was aware of any symptoms as a result - and, some 50 years later, I still seem to be going, with no more fatigue and muscle aches/pains (or other symptoms) than i can blame on the ageing process
That house still had it's all-lead plumbing when it was eventually sold in 1987, and that may possibly still be the case today.