While climbing on Iceland's Eyjafjallajökull glacier in March 2010, I might have dug my crampons in a tad too deep. A fortnight later, the volcano beneath the ice blew its top, causing widespread flight chaos.
Sorry about that.
Then, in March 2012, an underwater eruption off El Hierro, the smallest of the seven Canary islands, rained ready-cooked fish on to the quay at La Restinga. I was there the week before.
I'm telling this to adventure guide Eva Rodriguez Mateos over breakfast in the Parador del Teide (paradores.es) in central Tenerife, a one-hour, twisty-turny drive up through the clouds from the resorts of Costa Adeje.
"Tenerife has 321 volcanoes, but only two are active," Eva says, pointing to the near horizon. "That big one, and the one beside it."
That "big one" is Teide, the tallest mountain on Spanish territory, whose pointy peak is 3,718 metres above sea level (the height of three Carrantouhills). It last erupted - well, burped - in 1909, causing panic but little harm. The one beside it, Pico Viejo (3,135m), burst its western flank in 1798, in a mega-explosion that shot ash and car-sized boulders one kilometre into the air. The lava flowed for 99 days.
"Teide is considered unstable, but scientists tell us the next major eruption may not happen for thousands of years," Eva says, answering my unasked anxious question. "However, now that you're here...."
Both volcanoes lord it over El Teide National Park, where an up-with-the-larks trek to avoid the lunchtime tourist hordes (the park gets around four million visitors a year) is my introduction to two days of exploring Tenerife's wild natural landscapes. They're wildly diverse, too, from near-barren desert to lush rainforest and from fertile valleys planted with fruit trees and vines to lofty sea cliffs.
Dublin-based CanariaWays.com, with whom I'm travelling, recently added sunny-year-round Tenerife to its selection of European trails so outdoors enthusiasts can enjoy winter walks when northern Spain's pilgrim routes call for wellies, woollies and waterproofs.
It's shorts and T-shirts weather at 9am in early September as Eva leads the way among the Teide lava fields and spectacular rock formations where 1966 movie One Million Years BC, starring Raquel Welch as cavewoman Loana the Fair One, was filmed. Tenerife, as we know it, is three million years old and was formed by the volcanic fusion of three much more ancient islands; Teide and Pico Viejo are the 'stumps' of a colossus that collapsed 160,000 years ago.
We begin our four-kilometre circuit from the multi-layered Stone Tree, a top-heavy standalone formation with a skinny base that looks like it might topple at any moment. Eva reassures me it's safe, but with my track record - the Azure Window sea arch on Malta's tiny neighbour, Gozo, collapsed in March 2017, two days after I took a picture of it - I give it a wide berth.
The walk is mostly on the flat, but with a handful of steepish hillside tracks that can be tough on dodgy knees and ankles. On the whole, though, it's an easy two-and-a-half hours, affording views of the Ucanca plain stretching to the distant peaks and an up-close look at the 120-metre-tall magma mountain called La Catedral.
You can stand on Teide's summit by taking the cable car and walking the last 200m. Those with time, a sleeping bag and a permit obtained online can embark on a seven-hour trek from the base and spend the night in a hut 500m from the top before setting off an hour before dawn to catch the sunrise.
The sun has been up for only an hour when, next morning, minibus driver Mateo takes us from La Quinta Roja Hotel in Garachico (quintaroja.com), on the north coast, to the Parque Rural de Anaga, in the northeast, for an entirely different experience.
Today's 10km trek looks innocent enough on the map, and a walk through the dense and humid rainforest and along clifftop paths to the black volcanic sand beach just after the halfway mark proves a doddle.
"Rainforest" is a bit of a misnomer as there's little precipitation on the Anaga massif, so the trees, mostly lichen-coated laurel and lime, take water from the blanket of clouds that burns off by midday. From the beach, up through the Afur ravine to the hilltop hamlet of the same name, is a delightfully scenic but challenging climb that demands a level of fitness and stamina that may be beyond casual walkers.
Our group sets off together, but is soon strung out along the trail, and there are two hours between the first and last of us reaching the little café at the top, the sight of which is greeted like an oasis in the desert. Sitting on the terrace in the late afternoon sun, I re-enact the journey's end bar room scene from Ice Cold In Alex with a chilled glass of lager and immediately order another.
Over a farewell dinner in the Gran Hotel (lalagunagranhotel.com) in the lovely former island capital of La Laguna, Eva asks where my next trekking trip will be, and I tell her I'm off soon to Sicily.
"Ah, home to Mount Etna - Europe's most active volcano," she says. "What could possibly go wrong?"
Tom was a guest of CanariaWays.com, which offers self-guided walking holidays in Tenerife from €570pps B&B (four nights), including two dinners, transfers, info pack and 24/7 helpline. Flights are extra.
Tom flew with Aer Lingus (aerlingus.com) which operates up to seven flights a week from Dublin to Tenerife and up to two flights a week from Cork during its winter schedule. Fares from €66.99 one-way.
Solar radiation at altitude is deceptively strong, so sunscreen and a hat are vital. Boots should be worn-in. Bring blister pads, plasters and antiseptic cream. Give feet and insides of footwear a blast of anti-bacterial spray before and after walks. Backpacks should always contain a litre of water.
Griffon vultures were circling above as we climbed steadily on day two of our Camino. The swooping birds didn't so much have their eyes on our meaty - dare I say, toned - calves. They were indulging in a playful flyover because they knew something we didn't.