I think of a lot of things. Recently, when the trees were finally forming leaves, I was thinking about chlorophyll. The area is finally turning green and the amount of chlorophyll being produced by trees is no doubt in the "ton" range.
I got to thinking about the visible spectrum of chlorophyll a and b. Here is a picture from Wikipedia:
Do you notice anything? Look at the spectrum again and think about it for a second.
Let me ask you this: Why do leaves (most of them) look green?
Yup, because they don't absorb the green wavelengths of light. They don't absorb anything in the 500-550 nm range. In other words, green plants reject the color green!!!!
Allow me to personify. Plants hate green and they will have nothing to do with it. That is why they do not absorb green wavelengths of light. Plants DO like blue and red light. They absorb those wavelengths with glee. Plants hate green and love blue and red.
If you care about plants (and I hope you do because your survival depends on them) you should have the courtesy to reject what plants reject: GREEN.
I'm in favor of plants so I will not "Go Green" for anything. I will "Go Red and Blue". That's what plants like, and I like plants.
 We're still waiting for solid Spring weather.
 That would be an interesting calculation to figure out what mass of chlorophyll (all types) are stored in one tree.