A nice swim. Hearing a favorite song. Cuddling with someone who likes your cuddles. Breathing a deep breath of freshened air. Treat food. Petting a pet who enjoys being petted. Having, as Parry in The Fisher King said, "One of those really satisfying bowel movements, you know, the ones that border on the mystical." Getting work done and done well. Watching a gripping book, film, show, play, or other piece of entertainment. Walking in comfortable weather and getting to that viewpoint you love looking from. Tumbling, if you have the ability to do it well. Dancing, even if you don't have the ability to do it well. Taking your shoes off and letting your feet, after a long day, relax. Banter with the cool clerk or barista at that place you like to go to. Successfully napping where you like to do so, under that favorite blanket of yours.
Something like that will make you smile when you do it, or even simply think of doing it.
I hope something like that is easy for you to find, to think about, and to do.