Shila

Yes, feeling isolated in a crowd is a real phenomenon

, as loneliness is a subjective feeling of lacking meaningful connection, not just the absence of people. This sense of disconnection can arise from feeling misunderstood, being unable to express your authentic self, or the absence of strong, intimate social bonds, even when surrounded by many. 

Other drawbacks.

The primary limits to a theory of everything (ToE) are 

the inherent difficulty of unifying gravity with quantum mechanics, the lack of experimentally verifiable predictions, and the possibility of fundamental limits to knowledge, potentially demonstrated by Gödel's incompleteness theorems. Attempts to develop a ToE encounter conceptual and mathematical road blocks, such as the breakdown of the theory at singularities like those in black holes, and the inability to find evidence for new physics like supersymmetry. Furthermore, some physicists argue that the very nature of theories of everything might limit their completeness, and others suggest a ToE may not even exist. 

A "theory of everything" (ToE) is considered incomplete by some because 

Gödel's incompleteness theorem suggests that any formal mathematical system powerful enough to describe arithmetic will contain statements that are true but cannot be proven within the system itself. This philosophical argument suggests that even a perfect ToE would have inherent limitations, unable to describe all aspects of reality. However, most physicists don't see this as a definitive barrier, focusing instead on the practical challenges of unifying quantum mechanics and gravity and understanding observable phenomena like dark matter. 

The primary "controversy" surrounding the phrase "God is a spirit" centers on 

misinterpretations and differing theological views, particularly concerning the nature of God, the Trinity, and the concept of worship. Key debates include whether God's spiritual nature implies he is incorporeal and whether Jesus, having flesh and bones, can also be God. Some also clash over the meaning of "worship in spirit and truth" in John 4:24, with some Protestant traditions emphasizing an internal, invisible worship that eschews outward forms, while other traditions, like Catholicism, see spiritual worship as compatible with a more liturgical, external ritual.

A theory of everything (TOE) is a hypothetical, unified framework in physics that would describe all fundamental forces and particles in the universe within a single, consistent model, unifying general relativity (describing gravity and large-scale structures) with quantum physics (describing the subatomic world). While no such theory currently exists, it remains a major goal in physics to provide a complete understanding of the cosmos, potentially explaining phenomena like dark matter and dark energy. 

Yes, past memories are directly related to random thoughts

, as random thoughts are often a product of involuntary autobiographical memories that are triggered by a cue, emotion, or neural activity related to a past experience. The brain uses a mechanism called pattern completion to activate memories, so a partial activation of a past memory can lead to the full recall of that memory, even if it feels random. While often functional, if these memories become frequent, intense, or uncontrollable, they may be a symptom of a mental health condition, such as anxiety or OCD.