It's easy not the wear the seat belt. Sometimes it's hard to fasten the buckle when wearing large, bulky winter coats or jackets, and not buckling up happens in frustration. However that it's-too-hard-to-buckle-up becomes a behaviour which becomes the norm.
If your vehicle comes to a sudden stop, by hitting something, and you are not wearing a seat belt, you are usually launched out of the vehicle, usually through the windshield, and breaking an arm or leg as they come in contact with dash or side posts along the way. Most deaths of drivers/passengers involved in serious collisions or roll-overs, happen because they were not wearing seat belts.
So, if you have a death wish for yourself, and for your passengers, then of course, forget the seat belt. But if you want to live - wear the seat belt.
You don't know when or where a collision will occur, with you in the middle of it. Be prepared for life - to live. Pay attention - what's coming - don't become distracted - it's too easy I know, but bring yourself back to the road - your life may very well depend on it.
Good driving... hope you live ...
Cheers - Mike