It depends on how developed your Soul's «Energy System» is. Some people from birth may have opened Chakras, as well as probably manifestation of other abilities such as extra Psychic, Astral Projection, talent in Black Magic but this is not common, as it indicates the presence of great Spiritual merits in past incarnations.
If you are sensitive to Energy, you can feel if your Chakras are open. Focus on the Chakra area and project into it. If you have developed Astral Sight, you will be able to see the pulsation of the Chakra, its rotation and color. An open Chakra has its own rhythm of rotation and beating, as well as its pure natural color. An open Chakra always makes itself known, so Mental Projection can also help you to identify it. You can also feel the Chakra physically with this method by making it resonate in the body. This requires some skill, so many people have a problem with not feeling the Meditations. But with the establishment of a close contact between the Soul and the body, the feelings will be synchronized.
The reason why the Priests always insist on doing the Meditations daily is that if there is a long break, the accumulated energies dissipate because they are not condensed in the Soul, and the Soul is not developed to hold the energies within itself for long periods of time, as the Siddhis, for example, can afford to do. The energies settle in the physical shell, sensitivity is lost, and the connection with the Soul becomes unsynchronized. The energies accumulated over a lifetime are deposited in physical matter. That is why it is very important to fulfill at least the minimum standard daily.
If you cannot feel your Chakras, you can perform the 40-day program again. Then move on to the Complete Chakras Meditations. Also do not forget about the Extensions of the Chakras and about the Minor Chakras, which also need to be «energized».