If you're at a restaurant and you see someone having a rough time (like a kid having a meltdown), you can anonymously pay part or all of their bill and leave a note of support.

It happens, and people usually don't know how to help in the moment. I saw a post a few days ago about a dad having a very rough time at a restaurant with his autistic daughter. He ended up receiving a large anonymous tip and a note of support from another dad. I've done this a couple times after seeing kids basically having panic attacks at the table and needing to get outside, and once when I saw a couple on what appeared to be a first date start a little too friendly conversation with the very friendly waitress, realize their mistake, and start frantically trying to get their checks as the background began to spin around them. It's usually a small tip - $20 and a little note telling them to hang in there, parent/relationships are hard, and that sometimes it's okay to take your time getting out of there, but it always seems to catch them off guard in a positive way. Sometimes we need to remember to be gentle with each other.