One of the most common reasons why people lack the motivation to complete a particular task is because the task is not fun. Without this intrinsic motivation, people can be easily distracted or persuaded to do something else more enjoyable. Have you ever put off cleaning the bathroom to watch TV instead?
One way to motivate yourself to complete undesirable tasks is to find some way to make them fun. Sometimes it will be difficult to make things enjoyable, but if you have a little brainstorm, you can probably figure something out.
For example, to make cleaning the bathroom fun, you could:
1) Play some music and coordinate all your movements to the beat of the tune.
2) Set a timer and race against the last time you cleaned the bathroom. Try to be as efficient as possible.
3) Multitasking! Try to clean two things at once using both hands.
4) Pretend that you are fighting a war against a tiny dirt army. Your sponge is a bomber. Make airplane sounds.
5) Strap sponges to your feet and clean the tub without your hands.
Yeah, some of these may sound silly, but if you let your inner child out and have some fun, you may find that the task is easer to do.