I don’t know if you are a Nigerian or a foreigner but am going to try to make my answer cover for the two cases. I have only lived in lagos for a month It should be easy for me to point out obvious things that lagosian can't recorgnise. Lagos is the 5th most populous city in the world. Thats more than Tokyo , Moscow , London and Mumbai.
This is best explained using the basic aspect of living:
Work: Lagos is also the major Information Communications and Telecommunications (ICT) hub of West Africa and potentially, the biggest ICT market in the continent. I just get a job as a Developer in Lagos, We Developers tend to sit a lot in house average of 11hrs am in the office 4hrs on the road to and fro. That is too much time on the road for someone like me, Lagos has one of the largest and most extensive road networks in West Africa, I live about 15km from work which should be about 40 minutes journey to and fro. But the traffic is always huge even the so called Bus Rapid Transit (BRT) is always crowded.
Health: Lagos has many hospitals and medical facilities, some of which have accomplished feats in Nigeria's medical history. But here is the down side, The Lagos healthcare system is generally divided into public and private sectors which provide medical services at the primary, secondary and tertiary levels. Although the private hospitals are usually more expensive, it does not necessarily translate to better healthcare delivery. Four of the worst cities in the world for air pollution are in Nigeria. sometimes I feel like the air is choked, With 21 million people, Lagos is an industrial city the air is highly polluted, Traffic is increasing, emissions are not regulated and fuel tankers often catch fire on the streets. An estimated 7 million people were killed by diseases related to indoor and outdoor air pollution alone in 2012 according to the World Health Organization.
Learning: I noticed that Lagos has somany schools form basic to tetiary, some time I fear if they are all registered with the Government. Base on my social interaction the formal education system is doing great but not a lot of people work on personal development it seem no everyone has that patience. Money making seem to be the Number one priority most don't do it for the passion. The only way to do great work is to love what you do.- Steve Jobs. The education system is the 6-3-3-4 system, which is practised throughout the country (as well as by many other members of the ECOWAS). The levels are Primary, Junior Secondary School (JSS), Senior Secondary School (SSS), and university. All children are offered basic education, with special focus now on the first nine years. Many of the schools in Nigeria are federally funded and usually are boarding schools.
Social: Lagos is the centre of the Nigerian movie industry. Lagos is famous throughout Africa for its music scene. Lagos has a vibrant nightlife. The growth in its entertainment industry has impact on the increasing number of social activities that takes place across the city. I hardly pass a night without a disturbing night club musing sounds. Especially during the festive periods. 10 hotels, pubs and club houses were also closed because of background Noise. Middle class Lagosians love to drink beer. Am yet to understand why.
Spiritual: Nigerians are extremely religious, with a large number of evangelical churches operating in Lagos.
I have noticed that every lagosian have a soft spot for religion.
Note: Being religious doesn't mean they love God, Be careful don't get exploited.