I created this thread cos I saw a thread that says ladies shouldn't tell their real age early in a relationship.
And I felt it's not about the lady's age but the guy's age. Though his preference is someone younger.
Truth is most NL are in their teens to late 20's, I came to that conclusion cos of the comments I see here, that redpill was taken to a whole new level that is not in tandem with reality and most of these people have little to no experience when it comes to real life romance.
The OP is probably in his 20's too and prefer someone his age.
Now let's get to why I feel you should tell your age early

1. To avoid breakfast Someone that prefers younger girls will still want a younger lady, the earlier you tell him as a lady, the better for you, cos u might get too attached in the relationship when he finds out and trust me, breakfast hurts when you have gotten too attached. Ahh, this made me remembered mine. omoh, that thing deh break spirit.

2. trust what's the essence of lying about your age when he will still find out and stop trusting you, one thing that strengthens a relationship is trust, it takes alot of time to build and takes a second to break, well I am still building one, the babe no wan trust me even when I told her I am different from the ones she met, I am going through difficulties telling her I am genuine.

3. Peace of mind when he finds out, his behaviors towards you might change, he will come home late, you will be disgusting and irritating to him, You want peace abi, then don't lie, Nigeria already has enough problem to keep you awake, if you want to have heart attack go and check our foreign reserve, dollar rate or price of goods, one of these is enough to give u the jibiti that u want

4. You don't have to put too much energy to remember a truth no joke, it's easier to remember a truth than remember a lie, have you seen people lie effortlessly? Well those people are talented and you probably are not

5. Your man will come to you at no cost There are men looking for ur age, men who don't want a 21yr old lady, some men needs someone that is very mature in age, what's the essence of lying and getting hrtbreak when you can say the truth and find a man that loves you for who you are?

You're right
The guy who created that post is probably less than 25yrs, or even 20. I see most of his posts on Nairaland here and they're mostly juvenile.