It's hard. Guess it depends how busy your life is? At the moment for me training 4 days a week is an uninmaginable fantasy due to insane work and travel commitments. I manage 1 day, maybe 2 sessions a week. Just make sure the diet is spot on if your training drops.
And also, as you age, priorities and interests change. I've not wanted 'big muscles' since a few years now. I'm just happy with being in shape. If being 'huge' was a must for me, I'd pick up the needle like all other big guys on here. My life has moved on from spending endless hours in the gym or fretting about my bench numbers. It just doesn't matter any more. My goals have changed and for the moment are more career orientated.
Busy enough, but not too much to go to the gym 4-5x a week. People who say they have no time have either never exercised seriously, or don't want to. It's like any excuse system - there's always a way out if you want one.
The second paragraph is more astute and relevant. Lifting was my life from 19-24. I'd get up in the early morning, go do my cardio at a small local gym, come home, shower/eat, then go to a bigger gym for my real workout. Did that 5-6 days a week. Was on the diet, got lean enough to pass for a swimsuit-style magazine model with decent arms/legs, and was genuinely happy with my look.
Then I got older and less competitive. Being big or lean didn't matter as much. Women started to care less about that and more about other things. I quit clubbing. The diet got boring and I went back to eating like a normal person, which in my case means about 2000kcal more than average (appetite holdover from rugby). I put on weight. The gym became less attractive. I'm injured in several muscle groups. And finally I quit working out altogether 8 months ago. It shows. I'm smaller than I used to be even 3 years ago, and obviously not lean anymore. I'd say I look about how bigmc was in that guitar video. It's a long road back and I usually run out of steam about a few weeks.