When you paint you don't have to stay within the lines, but if you're painting a room in your house you probably should. Taking the extra time to tape it off so the paint doesn't bleed where it shouldn't is well worth it in the long rung from creating extra work. Painting is an art. Rushed painting is a mess. If you have time to prep the room on one day and paint the next, your mind will be fresher for your painting and sticking within the lines. Teach your children the same concept in life, not to rush and the outcome is much better.