The following several sutras of Patanjali are dedicated to one’s developmental rate:
तीव्रसंवेगानामासन्नः ॥ २१॥
tīvra – utmost, extreme, ultimate;
saṃvegānām - intention;
āsannaḥ – near, proximate;
that is, taking into account the previous line that says that prajna is preceded by shraddha, virya, smritiand samadhi, this one can be understood and translated in the following way:
1.21. Near under ultimate intention.
That is, the distance (probably, the temporal)between enlightenment (prajna) and its preceding stages shall not be big if a person is ultimate in his totality. It is clear by intuition: comprehension mayoccur only if you are totally engaged in pondering over the problem. This very principle can be applied to any other kind of development – quality transformations may only result from efforts that are thorough enough. Spiritual practice is not something that can be done “in the course of” and “together with” etc. It’s like V.Suvorov had it in his work “Aquarium” – “You cannothave you muscles built by lifting an iron twice a day».