According to Osho, when we panic about realizing enlightenment we retreat into the mind: we become cautious, calculate, and try to 'let go' carefully. This turns the glimpse into a mere intellectual feeling that quickly fades. Only a total, unreserved surrender - risking even psychological 'death' - reveals our deathless nature and the oceanic ecstasy beyond mind and body.
If you get scared and hold on, you miss it; relax completely, like floating on water, and it happens by itself.