My cat is not yet matured?

I have a grey persian tomcat whose now 1.5yrs old but Im worried since he hasn't "matured" yet, he doesn't spray all over the place [lucky me!] neither does he cry in a boisterous tone.May be this is because he is a complete house cat,dsn't know the outside world,he eats well and is active too.Is it a matter of concern that he doesn't feel like mating yet?will this affect his wellbeing?Should i take proactive steps by taking him front of a female cat or should i just wait?