Why dont we...

There are a lots of things we all know but we still never follow them..i have created a list of some such questions..feel free to give me more such things which u feel can be added:

Why don't we eat healthy when we all know about the damages junk food does to our health?

Why are Junk foods so tasty and tempting? Y don't healthy foods tempt us so much?

Why don't we exercise when we know that its the only way to ourselves to keep fit?

Why don't we love Mondays other than when its a holiday or our birthday?

Why don't we grow more trees when we know its for our better future??

Why don't we remain always kids?? Why do we even grow up??