I was feeling down one day, and went to the bank to pay a bill. The very nice young male cashier dealt with my bill, and as he finished, he said "I really like your hair".
Now I was old enough to be his mother, so it was a most unexpected compliment, and it really cheered me up!
Yesterday, I staggered to my local shop feeling rough with The Cough, to get some meds and hot toddy ingredients, and the young chap at the till asked me how I was, so I said I wasn't feeling well. Anyway, we exchanged a few anecdotes about having colds and coughs, etc., and then as I turned to leave, he said "I do hope you feel a lot better soon".
That was nice.
It really is the simplest things that can make a difference.