Sleeping bags/tents a yesyes or nono. in Western Europe?

Of course besides my backpack I have a small sleeping bag and backpack I use for hiking. Is it adviseable to bring it along or is it just not an option to use in Amnsterdam,London,Luxembourgh,Rome,Athens?Note the probably traditional route. However traveling during the high season

I'd suggest that is impossible to go to any of these cities and don't get a bed in a hostel. Almost all hostels won't let you use your sleeping bag due to possible bed bug infestations... But I'd take it just in case, anyway - you might do some camping or something.

I agree, it's also highly unlikely that the hostels won't have a kitchen-sink provided, but I'd take one just in case, anyway - you might do some light plumbing work or something.

I wouldn't lug a sleeping bag all around with me, on the off chance, when one can be got in europe, (or even just blankets) for very little.

Actually, I usually carry a universal sink-stopper. Weighs about ten grams and has proven its worth a thousand times.

When you can get sleeping bags slightly larger than the size of your fist, there really isn't an argument against taking one. Especially if travelling around with a large pack, like most backpackers....

I shed my stuff fast when I was travelling. At the end, I only had a small shoulder bag and a small sleeping bag. You can buy anything you need as you need it, in most areas.

I don't like doing that when on a rock-bottom budget. €20 a day is sometimes difficult

In America, I can buy you an entire new wardrobe for 20 Euros, at garage sales or at any of the thousands of thrift stores across the country.

America is not Western Europe.