I can be long, I can be short, I might sound silly, or quite sort. I’m written on your birthday cake,

I hold your dirty laundry tight, and keep it tucked away from sight. Yet in another role I play, I slow your plans or block your way.

If you change my first letter, I can become many things. B for water at one hundred degrees Celsius. F for cooking on a grill. T for working hard. S for earth. I'm the posture of a snake.

Created by mistake, your food I will bake. Or nuke as you may say, though dryness I will convey.

I've been told I drag you down, but that's kind of the point!