In order to understand men you need to understand the male biology and psychology, which is not difficult to do, it is primal in nature and there are some simple basics.
Men are hard-wired in a very different way than women, and although we have evolved into a higher form of being above the animal kingdom, many of those animal instincts affect men and women to this day. So how do we begin to understand the male animal?
Men, first of all, have less synapses in their brains connecting the left (thinking) hemisphere, and the right (feeling) hemisphere of the brain. What this means is that men take a bit longer to translate thoughts into feelings and to understand the reasons for their feelings. It is harder for a male, biologically, to get in touch with his feelings than it is for a female, who has more synapses connecting her thoughts and feelings.
Men also have the primal instinct to breed with and impregnate as many females as possible in order to ensure propagation of the species. This is why men are more prone to infidelity within relationships than women. The evolved male will resist the temptations once committed, but the pleasure seeking male may well not allow prior commitments to prevent his immediate gratification from occurring.
Men have some fairly basic psychological needs. The male ego needs to feel a sense of trust and respect, if you are always doubting what the man in your life says, his intentions and motives, it will undermine his need to feel trusted and may well push him away. Give him the benefit of the doubt unless you have good reason to think he is being dishonest and you will go far in gaining his affection.
The need to feel respect means that if you have an issue or a problem, he's likely to help you, he wants you to have confidence in his abilities, so don't be afraid to discuss your issues with him. He may not actually "fix" things for you, you have to do that, but listen to his advice and let him know you appreciate him trying to assist you.
Don't constantly communicate 24/7 with him, you don't have to make him feel that you are insecure (lack of trust) about him. This is an issue with many men. When he receives twenty text messages a day from you he is going to tire of the constant barrage of messages and cease responding and probably cease initiating communication.
When you are apart for your day at work attend to your own business and allow him the space to feel he misses you. He will be much more attentive if he gets a chance to miss you being a part of his day than if you are always there at the touch of a button.
Men aren't that difficult to understand, give them space, respect, trust and they will show you that they care and are interested in you too.