Does Not Having Night Falls Mean That A Person Is Sexually Weak ?

i m 30 year old, married man. i am in habbit of masturbating since i was 12 years old. i used to masturbate 2-3 times a week and so, i never had night fall. once, i abstained from masturbation for a month and even then, i didnt have night fall. i once abstained for more than 3 months and it was only then that i had my first ever night fall of my life at the age of 25 years. i m married now and am away from my wife due to job reasons. even if i dont masturbate now, i dont have night falls. my friends tell me that it is necessary to have night falls and if u r not having it, u r sexually weak . i m upset because of this. how frequent should one have night fall? i had experienced it only twice till date.