Full kundalini awakening makes a seeker reach state of Gudakesha, one who has overpowered sleep forever. Lord Krishna was also known as Gudakesha.
Every enlightened one finally overcomes sleep forever. This aspect of sleeplessness has two facets in life, one spiritual and the other physical.
On spiritual scale Gudakesha (one who overcomes sleep) means one indulging in jnana yoga (absolute wisdom) finally overcomes darkness of ignorance forever.
On the physical plane a Gudakesha actually overcomes sleep forever. In 1993 the moment I realized god, realized self I could cover eight hours of sleep in five minutes.
When I asked my father permission to run my office in three shifts of eight hours each, he bluntly refused. I managed with only two shifts totaling 16 hours.
In absence of dross impurities within, having become a pure soul atman the need for resting the body for full eight hours every single day depletes to the extent that only five minutes of rest gives freshness equivalent to 8 hours of sleep.
Indulging in spirituality, reaching cosmic end of life, full kundalini awakening is something that can only be experienced, never described in words.