Picking up litter has been a regular action most of my life. My grandparents, parents, and uncles all taught me that this was my responsibility and is a responsibility for all of us. Beyond them all being involved in Boy Scouts and Girl Scouts, including as professional leaders, they also were/are frequent participants in park and beach clean-ups. I can never walk down the beach and not pick up particles of trash, if possible.
In addition, I actually was an Earth Guardian at the Burning Man Festival for many years, as one of the core educators and researchers on their Leave No Trace (LNT) practices. Litter is known as MOOP (Matter Out Of Place) on the playa, which is within the Black Rock Desert and managed by the Bureau of Land Management. That was a powerful era in my life and LNT is still a daily mantra for me.