No, there are many ways to experience the delirium and psychosis of a solipsistic mindset. Fever dreams, depersonalisation, brain damage and schizophrenia, to name a few. High doses of hallucinogens can also get you there, but only if you're confused about what you're doing. Case in point: my first trip, on mushrooms (still the heaviest trip I've ever had, counting DMT and ayahuasca), which became literally crazy around the time I concluded I had created everything as a way to occupy my lonely eternity, and nobody I knew had ever really existed.
Life is a hallucination and everything we perceive is a projection of the mind. But that's where a lot of people get stuck. They assume this means it isn't real. They don't realise that they are inseparable from the contents of the hallucination. To exist at all, you need an environment, a context, to exist within. That's what life is. To perceive yourself at all, you also need a sense of other, the parts of the dream which you are not consciously deciding upon. Without spontaneity and unpredictability, without chaos, it would not be life at all. In other words: however real the world is, that's how real you are, because the two are the same thing.
Solipsism isn't a desirable state to reach. As a thought experiment, it's engaging if misguided. As an experience, it's just another form of insanity.
