Can you actually prove that your Hamster really exists?
It may be an hallucination. Hallucination is the perception of something that does not exist. It may be visual but may also arise from any of the other senses, so you could not only see your hamster but touch and smell it just like the real thing. You may be suffering some sort of psychosis, a common symptom of this is hallucination, often accompanied by false beliefs (so a paranoid psychosis is that you believe people are out to get you and may even hear voices telling you this, in a paranoid hamster psychosis, you may believe that your hamster is out to get you...even if you donít HAVE a hamster).
You may be missing sleep. Sleep is a state of natural unconsciousness and activity that occurs at regular intervals in most mammals and birds, though there is considerable variation in the amount of time spent sleeping. Sleep differs from hibernation in that it occurs daily rather than seasonally, and involves less drastic reductions in metabolism. The function of sleep is unclear, however people deprived of sleep become irritable, uncoordinated, forgetful, hallucinatory, and even psychotic. Go to bed and see if your hamster is still there the next morning.
You may have a brain disease - particularly temporal lobe epilepsy which is often associated with hallucination. Donít worry, this can be controlled by anticonvulsant drugs.
Mind you it could be that your hamster is simply due to drugs, in which case, stop and maybe your hamster will go away.
It may be an illusion. Generally, illusions are delusions, deceptions, or false perceptions. You may genuinely think you have a hamster but you donít, you are just temporarily deceived, either by yourself or someone else. You should go up to the cage and poke your so called hamster. If it turns out to just be a stuffed toy, you were deceived and your hamster ownership was just an illusion. Alternatively it may be something like a banana but you donít recognise it as a banana because you are deceiving yourself. This may be a psychosis (see above), or maybe you donít really know what a hamster is, in which case you need to be taught what is a banana and what is a hamster in order to shatter your illusion...assuming you trust the person who is telling you it is a banana, but then it is only by trusting some experiences that we can identify others as illusory, and the occurrence of illusions does not mean that everything is illusory.
Depending on your philosophical bent, you may be follow idealism - which states that the external world is fundamentally immaterial and a dimension of the mind. Therefore your hamster exists, but, according to this theory, it lacks substance.
Alternatively you may follow scepticism - which states that absolute knowledge of things is ultimately unobtainable, hence the only proper attitude is to suspend judgement. The origins of this theory lie in the teachings of the Greek philosopher Pyrrho, who maintained that peace of mind lay in renouncing all claims to knowledge. Therefore you shall never be able to prove that your hamster exists, so you may as well not bother.
So finally... I ask you again - does your hamster *still* exist? Not sure? Canít answer? Then perhaps you will never be able to...