You'll tend to feel soreness (I'm assuming that's what you mean by ache) in your muscles when you do a new lift that's semi-difficult, or when you do a particularly hard workout session. If you workout, wait a month doing nothing, then workout again, you'll probably be sore both times.
To get sore again? Either you can do 1 of 2 things (probably others but thesse are simple)
1. Workout really hard, your muscles should be completely dead when you finish. Barely able to move without overextending and hurting yourself (that'll give you a different type of ache

)
2. Workout in a different way, I'm guessing you're lifting weights? Do a different type of the lift, maybe DB instead of BB bench press. Or eccentric, or anything slightly different. If it's to similar or not hard enough you won't get sore, but working different ways will help.
Hope I could help!