I think it’s okay to be sad on some days. I don’t believe that all days should be alike. I am a writer by profession but I also paint. On days that I feel low I spend quiet time with my canvas. I allow myself to soak in the emotion letting it all come out in the form of colors.
If there's ever a day when the little things just don't seem to be enough to keep your spirits up, then that's okay. But, just remember that some people don't even get to have the little things.
It's all about knowing yourself. What makes me happy changes constantly. I used to love pampering myself with a diy Mani/pedi. Now it's sitting in the sun for a little while and feeling the breeze or watching my son grow and learn. Go through a week and every time you find that you even feel a tiny bit of happiness, state that this makes you happy, make a mental or physical note of it. And then do that activity more often. I get lost sometimes in between the changes of growing up and what makes me happy. It can feel like you are on a rocky boat. It's all about seeking that shoreline. Don't focus too much on the boat
If on some days, the little things are not enough to cheer me up I just sit with my present feelings without any effort to get out of it or any judgement on myself or life. I tell myself "this too shall pass".